WO2016053637A1

WO2016053637A1 - Preparation and applications of hydrophobic materials

Info

Publication number: WO2016053637A1
Application number: PCT/US2015/050710
Authority: WO
Inventors: Michel Deeba
Original assignee: Basf Corporation
Priority date: 2014-09-29
Filing date: 2015-09-17
Publication date: 2016-04-07

Abstract

Described are hydrophobic materials treated with a hydrophobic source in order to enhance their hydrophobicity. The hydrophobic materials can comprise a catalyst and/or a sorbent. These hydrophobic materials have utility in a broad range of applications, e.g. separating hydrocarbons from water, removing volatile organic compounds from the ambient atmosphere, the management of oil spills, removing hydrocarbons from an exhaust gas stream, chemical separation processes to remove non-polar substances, and reducing NO_x in the exhaust gas stream of a lean burn engine.

Description

PREPARATION AND APPLICATIONS OF HYDROPHOBIC MATERIALS

TECHNICAL FIELD

[0001] The present invention relates generally to materials that have a hydrophobic surface treatment and are able to repel water or other hydrophilic materials. More particularly, the invention relates to a hydrophobic material that is impregnated with a hydrophobic component in order to increase its hydrophobicity.

BACKGROUND

[0002] Materials such as zeolites, metal oxides, mixed metal oxides, and different ceramic and crystalline materials are generally hydrophilic in nature. These materials are usually prepared in particulate form to manufacture catalysts and sorbents. In one non-limiting example, particulate zeolites, metal oxides and/or mixed metal oxides are prepared as slurries in a liquid medium, known as a washcoat, and the washcoat is applied to a substrate such as a honeycomb substrate, dried, and calcined to form a catalytic article. In many applications, catalysts and sorbents encounter aqueous and humid environments. Due to the hydrophilic nature of some of these materials, the ability of the materials to repel water or separate hydrophobic compounds is therefore limited.

[0003] Hydrophobicity is generally defined as a physical property of a molecule that is seemingly repelled from a mass of water. Hydrophobic molecules tend be non-polar, and, thus, prefer other neutral molecules and non-polar solvents. Hydrophobic molecules in water often cluster together. Examples of hydrophobic materials include alkanes, oils, fats, and greasy substances in general.

[0004] Hydrophobic materials may be used for a broad range of applications. For example, hydrophobic materials have utility for oil removal from water and water-containing atmospheres, the management of oil spills, and chemical separation processes to remove non-polar substances from polar substances.

[0005] There is a need, therefore, for enhancing the hydrophobicity of generally hydrophilic materials.

SUMMARY [0006] A first aspect of the invention pertains to a hydrophobic material. In a first embodiment, a hydrophobic material for use as a catalyst or sorbent comprises a particulate material component impregnated with a hydrophobic component, the hydrophobic material effective to repel one or more of water or a hydrophilic material from a surface of the particulate material component, wherein the particulate material component comprises one or more of a molecular sieve, a metal oxide, a mixed metal oxide, a non-zeolitic material, a clay material, a rare-earth oxide, a mesoporous material, and an activated refractory metal oxide, wherein the hydrophobic material is effective as a sorbent or catalyst.

[0007] In a second embodiment, the hydrophobic material of the first embodiment is modfied, wherein the hydrophobic components is selected from one or more of a fluorine component, a silica component, a siliconfluoride, polytetrafluoroethylene, and a hydrophobic silicone polymer.

[0008] In a third embodiment, the hydrophobic material of the first and second embodiments is modified, wherein the hydrophobic component comprises a fluorine component.

[0009] In a fourth embodiment, the hydrophobic material of the third embodiment is modified, wherein the fluorine component is not obtained from gaseous ammonium fluoride.

[0010] In a fifth embodiment, the hydrophobic material of the third and fourth embodiments is modified, wherein the fluorine component is obtained from a fluorine source comprising one or more of fluorine gas, ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non- metal fluoride.

[0011] In a sixth embodiment, the hydrophobic material of the fifth embodiment is modified, wherein the metal fluoride salt is selected from lithium fluoride (LiF), calcium difluoride (CaF₂), GpIA, GpIIA, hexafluorosilicic acid (SiF₆), phosphorus trifluoride (PF₃), fluorosilicic acid, A1F₃, BaF₂, CdF₂, CeF₂, Na₃AlF₆, HfF₄, LaF₃, PbF₂, MgF₂, KF, rare earth fluorides, NaF, ThF₄, yttrium barium fluoride, yttrium calcium fluoride, and combinations thereof. These fluoride salts may be in a water solution.

[0012] In a seventh embodiment, the hydrophobic material of the fifth embodiment is modified, wherein the fluorine source comprises ammonium fluoride solution.

[0013] In an eighth embodiment, the hydrophobic material of the fifth embodiment is modified, wherein the organo fluoride is selected from CH₃F, CH₂F₂, CHF₃, CF4, fluoro ethane, fluoropropane, flourobutane, fluorohexanes, fluorobenzene, nafeon polymer, fluoroaromatic compounds, trifluoroacetic acid, and combinations thereof. [0014] In a ninth embodiment, the hydrophobic material of the fifth embodiment is modified, wherein the non-metal fluoride is selected from boron trifluoride (BF3), phosphorus trifluoride (PF3), HF, and combinations thereof.

[0015] In a tenth embodiment, the hydrophobic material of the first through ninth embodiment is modified, wherein the molecular sieve has a structure type selected from the group consisting of MFI, BEA, AEI, AFT, AFX, CHA, EAB, EMT, ERI, FAU, GME, JSR, KFI, LEV, LTL, LTN, MOZ, MSO, MWW, OFF, SAS, SAT, SAV, SBS, SBT, SFW, SSF, SZR, TSC, WEN, and combinations thereof.

[0016] In an eleventh embodiment, the hydrophobic material of the first through tenth embodiments is modified, wherein the molecular sieve is promoted with a metal selected from Pt, Pd, Rh, Ru, Ir, Cu, Fe, Co, Ni, La, Ce, Mn, V, Ag, and combinations thereof.

[0017] In a twelfth embodiment, the hydrophobic material of the first through eleventh embodiments is modified, wherein the non-zeolitic material is selected from kaolinite, halloysite, montmorillonite, bentonite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, clay, gibbsite (alumina trihydrate), boehmite, silica-magnesia, magnesia and sepiolite.

[0018] In a thirteenth embodiment, the hydrophobic material of the first through twelfth embodiments is modified, wherein the mesoporous material is selected from SBA-15, SBA-22, MCM-41 , and modified mesoporous materials.

[0019] In a fourteenth embodiment, the hydrophobic material of the first through thirteenth embodiments is modified, wherein the hydrophobic material is selected from a catalyst or sorbent, or combinations thereof.

[0020] A second aspect of the present invention is directed to a catalyst. A fifteenth embodiment is directed to a catalyst comprising an SCR component impregnated with a fluorine component, the catalyst effective to repel water from a surface of the SCR component.

[0021] In a sixteenth embodiment, the catalyst of the fifteenth embodiment is modified, wherein the SCR component comprises Cu-SAPO-34, CuTiAPSO, CuCHA, CuZSM-5, FeZSM- 5, Cu Beta, or Fe Beta.

[0022] A third aspect of the present invention is directed to a catalyst. A seventeenth embodiment is directed to a catalyst comprising a hydrocarbon trap component impregnated with a fluorine component, the catalyst effective to repel water from a surface of the hydrocarbon trap component.

[0023] A fourth aspect of the present invention is directed to a method. An eighteenth embodiment is directed to a method comprising: providing a material having a hydrophobic surface treatment selected from a fluoride impregnated on a surface of the material and an oxide that minimizes water adsorption on the material surface, the hydrophobic surface treatment effective to repel one or more of water and a hydrophilic material from the surface of the material; using the material having the hydrophobic surface treatment in an environment containing moisture, wherein the material is used as one or more of a catalyst and a sorbent, and wherein the hydrophobic surface treatment prevents moisture from interfering with catalytic activity and/or sorption of the material.

[0024] In a nineteenth embodiment, the method of the eighteenth embodiment is modified, wherein the method comprises removing a hydrocarbon contaminant from water.

[0025] In a twentieth embodiment, the method of the nineteenth embodiment is modified, wherein the hydrocarbon is selected from an alkane having C2-C30 carbons and the material comprises one or more of a molecular sieve, alumina (silica-alumina), silica, clay, bentonite, montmorillonite, kaolinite, halloysite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, gibbsite (alumina trihydrate), boehmite, silica-magnesia, magnesia, and sepiolite.

[0026] In a twenty-first embodiment, the method of the eighteenth embodiment is modified, wherein the method comprises removing volatile organic compounds from the ambient atmosphere, wherein the ambient atmosphere contains humidity.

[0027] In a twenty-second embodiment, the method of the eighteenth embodiment is modified, wherein the method comprises removing hydrocarbons from an engine exhaust stream and the material comprises a molecular sieve or a mesoporous material and the molecular sieve is for example as described in the tenth embodiment and the mesoporous material is for example as described in the thirteenth embodiment.

[0028] In a twenty-third embodiment, the method of the eighteenth embodiment is modified, wherein the method comprises reducing NO_x in the exhaust gas stream of a lean burn engine and the material comprises a base metal and a molecular sieve. [0029] In a twenty-fourth embodiment, the method of the twenty-third embodiment is modified, wherein the base metal comprises copper and the molecular sieve comprises SAPO-34.

[0030] A fifth aspect of the present invention is directed to a method. A twenty-fifth embodiment is directed to a method of increasing the hydrophobicity of a material, the method comprising impregnating a material with a fluorine source; calcining the impregnated material at about 150 to 550 °C; wherein the material comprises one or more of a molecular sieve, a metal oxide, a mixed metal oxide, a non-zeolitic material, a clay material, a rare-earth oxide, a mesoporous material, and an activated refractory metal oxide; with the proviso that the fluorine source does not comprise a gas.

[0031] In a twenty-sixth embodiment, the method of the twenty- fifth embodiment is modified, wherein the fluorine source comprises one or more of ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non-metal fluoride.

[0032] In a twenty-seventh embodiment, the method of the twenty-fifth and twenty-sixth embodiments is modified, wherein dealumination of the material does not occur.

DETAILED DESCRIPTION

[0033] Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

[0034] Embodiments of the invention are directed to materials which are generally initially hydrophilic and are transformed into hydrophobic materials by treatment with a hydrophobic. After treatment, these hydrophobic materials are capable of repelling water and other hydrophilic materials.

[0035] With respect to the terms used in this disclosure, the following definitions are provided.

[0036] As used herein, the term "catalyst" or "catalyst composition" or "catalyst material" refers to a material that promotes a reaction.

[0037] As used herein, the term "catalytic article" refers to an element that is used to promote a desired reaction. For example, a catalytic article may comprise a washcoat containing a catalytic species, e.g. a catalyst composition, on a substrate. [0038] As used herein, the term "sorbent" refers to a material used to absorb or adsorb liquids or gases.

[0039] As used herein, the terms "hydrophilic" and "hydrophilic material" refer to a material that has a tendency to interact with or be dissolved by water and other polar substances.

[0040] As used herein, the terms "hydrophobic" and "hydrophobic material" refer to a molecule or portion of a molecule that tends to repel, or not to combine with, or is incapable of dissolving in water.

[0041] As used herein, the term "hydrophobic component" refers to a component that is hydrophobic in nature and that can be applied to a hydrophilic material in order to increase the hydrophobicity of the material. In one or more embodiments, the hydrophobic component is selected from a fluorine component, a silica component, a siliconfiuoride, polytetrafluoroethylene, hydrophobic silicone polymer, and mixtures thereof.

[0042] According to one or more embodiments, a hydrophobic material comprises a particulate material component impregnated with a hydrophobic component. The hydrophobic material is effective to repel one or more of water or a hydrophilic material from a surface of the material component. In one or more embodiments, the hydrophobic material is selected from a catalyst or sorbent, or combinations thereof. According to one or more specific embodiments, a hydrophobic material comprises a particulate material component impregnated with a fluorine component.

[0043] As used herein, the term "fluorine component" refers to a component having a compound of fluorine. Fluorine forms a variety of chemical compounds, within which fluorine almost always adopts an oxidation state of -1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. In one or more embodiments, the fluorine component is obtained from a fluorine source comprising one or more of fluorine gas, ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non-metal fluoride. In other embodiments, the fluorine component is not obtained from gaseous ammonium fluoride. In one or more embodiments, the fluorine source comprises ammonium fluoride solution.

[0044] In one or more embodiments, the metal fluoride salt is selected from lithium fluoride (LiF), calcium difluoride (CaF₂), GpIA, GpIIA, hexafluorosilicic acid (SiF₆), phosphorus trifiuoride (PF3), fiuorosilicic acid, A1F₃, BaF₂, CdF₂, CeF₂, Na₃AlF₆, HfF₄, LaF₃, PbF₂, MgF₂, KF, rare earth fluorides, NaF, ThF4, yttrium barium fluoride, yttrium calcium fluoride, and combinations thereof.

[0045] In one or more embodiments, the organo fluoride is selected from CH3F, CH2F2, CHF3, CF4, fluoro ethane, fluoropropane, flourobutane, fluorohexanes, fluorobenzene, nafeon polymer, fluoroaromatic compounds, trifluoroacetic acid, and combinations thereof.

[0046] In one or more embodiments, the non-metal fluoride is selected from boron trifluoride (BF3), phosphorus trifluoride (PF3), HF, and combinations thereof. In specific embodiments, the fluorine component comprises boron trifluoride (BF3). Approximately about 2300-4500 tons of boron trifluoride are produced every year. In some embodiments, BF3 can be added from gas, since the boiling point of BF3 is about -100 °C.

[0047] In one or more embodiments, the particulate material component comprises one or more of a molecular sieve, a metal oxide, a mixed metal oxide, a non-zeolitic material, a clay material, a rare-earth oxide, a mesoporous material, and an activated refractory metal oxide.

[0048] As used herein, the term "non-zeolitic material" refers to a material that is not a zeolite or molecular sieve. As used herein, the non-zeolitic material can comprise binder and filler. According to one or more embodiments, the "non-zeolitic material" can be selected from the group consisting of kaolinite, halloysite, montmorillonite, bentonite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, gibbsite (alumina trihydrate), boehmite, silica- magnesia, magnesia and sepiolite.

[0049] According to one or more embodiments, the particulate material component comprises a molecular sieve. In one or more embodiments, an adsorbent molecular sieve framework is used to adsorb gaseous pollutants, usually hydrocarbons, and retain them during the initial cold-start period. As the exhaust temperature increases, the adsorbed hydrocarbons are driven from the adsorbent and subjected to catalytic treatment at the higher temperature. As used herein, the term "molecular sieves", such as zeolites and other zeolitic framework materials (e.g. isomorphously substituted materials), refer to materials, which may in particulate form support catalytic precious group metals. Molecular sieves are materials based on an extensive three-dimensional network of oxygen ions containing generally tetrahedral type sites and having a substantially uniform pore distribution, with the average pore size being no larger than 20 A. The pore sizes are defined by the ring size. As used herein, the term "zeolite" refers to a specific example of a molecular sieve, further including silicon and aluminum atoms. According to one or more embodiments, it will be appreciated that by defining the molecular sieves by their structure type, it is intended to include the structure type and any and all isotypic framework materials such as SAPO, ALPO and MeAPO materials having the same structure type.

[0050] In more specific embodiments, reference to an aluminosilicate zeolite structure type limits the material to molecular sieves that do not include phosphorus or other metals substituted in the framework. However, to be clear, as used herein, "aluminosilicate zeolite" excludes aluminophosphate materials such as SAPO, ALPO, and MeAPO materials, and the broader term "zeolite" is intended to include aluminosilicates and aluminophosphates.

[0051] Generally, molecular sieves, e.g. zeolite, are defined as aluminosilicates with open 3- dimensional framework structures composed of corner-sharing TO4 tetrahedra, where T is Al or Si. Cations that balance the charge of the anionic framework are loosely associated with the framework oxygens, and the remaining pore volume is filled with water molecules. The non- framework cations are generally exchangeable, and the water molecules removable.

[0052] In one or more embodiments, the molecular sieve comprises S1O4/AIO4 tetrahedra and is linked by common oxygen atoms to form a three-dimensional network. The molecular sieves of one or more embodiments are differentiated mainly according to the geometry of the voids which are formed by the rigid network of the (Si04)/A104 tetrahedra. The entrances to the voids are formed from 6, 8, 10, or 12 ring atoms with respect to the atoms which form the entrance opening. In one or more embodiments, the molecular sieves comprise ring sizes of no larger than 12, including 6, 8, 10, and 12.

[0053] According to one or more embodiments, the molecular sieves can be based on the framework topology by which the structures are identified. Typically, any structure type of zeolite can be used, such as structure types of ABW, ACO, AEI, AEL, AEN, AET, AFG, AFI, AFN, AFO, AFR, AFS, AFT, AFX, AFY, AHT, ANA, APC, APD, AST, ASV, ATN, ATO, ATS, ATT, ATV, AWO, AWW, BCT, BEA, BEC, BIK, BOG, BPH, BRE, CAN, CAS, SCO, CFI, SGF, CGS, CHA, CHI, CLO, CON, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EMT, EON, EPI, ERI, ESV, ETR, EUO, FAU, FER, FRA, GIS, GIU, GME, GON, GOO, HEU, IFR, IHW, ISV, ITE, ITH, ITW, IWR, IWW, JBW, KFI, LAU, LEV, LIO, LIT, LOS, LOV, LTA, LTL, LTN, MAR, MAZ, MEI, MEL, MEP, MER, MFI, MFS, MON, MOR, MOZ, MSO, MTF, MTN, MTT, MTW, MWW, NAB, NAT, NES, NON, NPO, NSI, OBW, OFF, OSI, OSO, OWE, PAR, PAU, PHI, PON, RHO, RON, RRO, RSN, RTE, RTH, RUT, RWR, RWY, SAO, SAS, SAT, SAV, SBE, SBS, SBT, SFE, SFF, SFG, SFH, SFN, SFO, SGT, SOD, SOS, SSY, STF, STI, STT, TER, THO, TON, TSC, UEI, UFI, UOZ, USI, UTL, VET, VFI, VNI, VSV, WIE, WEN, YUG, ZON, or combinations thereof.

[0054] Zeolites are comprised of secondary building units (SBU) and composite building units (CBU), and appear in many different framework structures. Secondary building units contain up to 16 tetrahedral atoms and are non-chiral. Composite building units are not required to be achiral, and cannot necessarily be used to build the entire framework. For example, a group of zeolites have a single 4-ring (s4r) composite building unit in their framework structure. In the 4-ring, the "4" denotes the positions of tetrahedral silicon and aluminum atoms, and the oxygen atoms are located in between tetrahedral atoms. Other composite building units include, for example, a single 6-ring (s6r) unit, a double 4-ring (d4r) unit, and a double 6-ring (d6r) unit. The d4r unit is created by joining two s4r units. The d6r unit is created by joining two s6r units. In a d6r unit, there are twelve tetrahedral atoms. Zeolitic structure types that have a d6r secondary building unit include AEI, AFT, AFX, CHA, EAB, EMT, ERI, FAU, GME, JSR, KFI, LEV, LTL, LTN, MOZ, MSO, MWW, OFF, SAS, SAT, SAV, SBS, SBT, SFW, SSF, SZR, TSC, and WEN.

[0055] In one or more embodiments, the molecular sieve comprises a d6r unit. Thus, in one or more embodiments, the molecular sieves have a structure type selected from AEI, AFT, AFX, CHA, EAB, EMT, ERI, FAU, GME, JSR, KFI, LEV, LTL, LTN, MOZ, MSO, MWW, OFF, SAS, SAT, SAV, SBS, SBT, SFW, SSF, SZR, TSC, WEN, and combinations thereof. In other specific embodiments, the molecular sieves have a structure type selected from the group consisting of CHA, AEI, AFX, ERI, KFI, LEV, and combinations thereof. In still further specific embodiments, the molecular sieves have a structure type selected from CHA, AEI, and AFX. In one or more very specific embodiments, the molecular sieves have the CHA structure type.

[0056] In one or more embodiments, the molecular sieves are selected from an aluminosilicate zeolite, a borosilicate, a gallosilicate, a SAPO, an A1PO, a MeAPSO, and a MeAPO. In specific embodiments, the molecular sieves comprise ZSM-5. In other specific embodiments, molecular sieves have the CHA structure type and are selected from the group consisting of SSZ-13, SSZ- 62, natural chabazite, zeolite K-G, Linde D, Linde R, LZ-218, LZ-235, LZ-236, ZK-14, SAPO- 34, SAPO-44, SAPO-47, and ZYT-6. In very specific embodiments, the molecular sieves have the CHA structure type and are selected from SSZ- 13 and SSZ-62. [0057] As used herein, the term "promoted" refers to a component that is intentionally added to the molecular sieve, as opposed to impurities inherent in the molecular sieve. Thus, a promoter is intentionally added to enhance activity of a material compared to a material that does not have promoter intentionally added. For example, in order to promote the SCR of oxides of nitrogen, in one or more embodiments, a suitable metal is exchanged into the material component (e.g. molecular sieves). According to one or more embodiments, the material component is promoted with a metal selected from Cu, Fe, Co, Ni, La, Ce, Mn, V, Ag, and combinations thereof. In specific embodiments, the material component is promoted with Cu, Fe, and combinations thereof.

[0058] According to one or more embodiments, the particulate material component comprises a mixed metal oxide. As used herein, the term "mixed metal oxide" refers to an oxide that contains cations of more than one chemical element or cations of a single element in several states of oxidation. In one or more embodiments, the mixed metal oxide is selected from Fe/titania (e.g. FeTi0₃), Fe/alumina (e.g. FeAl₂0₃), Mg/titania (e.g. MgTi0₃), Mg/alumina (e.g. MgAl₂0₃), Mn/alumina, Mn/titania (e.g. MnO_x/Ti0₂) (e.g. MnO_x/Al₂0₃), Cu/titania (e.g. CuTi0₃), Ce/Zr (e.g. CeZr0₂), Ti/Zr (e.g. TiZr0₂), vanadia/titania (e.g. V₂0₅/Ti0₂), and mixtures thereof. In specific embodiments, the mixed metal oxide comprises vanadia/titania. The vanadia/titania oxide can be activated or stabilized with tungsten (e.g. W0₃) to provide V₂0₅/Ti0₂/ W0₃. In one or more embodiments, the material component comprises titania on to which vanadia has been dispersed. The vanadia can be dispersed at concentrations ranging from 1 to 10 wt%, including 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10wt%. In specific embodiments the vanadia is activated or stabilized by tungsten (W0₃). The tungsten can be dispersed at concentrations ranging from 0.5 to 10 wt%, including 1 , 2, 3, 3. 4, 5, 6, 7, 8, 9, and 10 wt%. All percentages are on an oxide basis.

[0059] According to one or more embodiments, the particulate material component comprises a mesoporous material. As used herein, the term "mesoporous material" refers to a material having pores with diameters between 2 and 50 nm. In some embodiments, mesoporous materials include those modified mesoporous materials wherein Al, Zr, Ti, and Ce are substituted into the framework structure. In one or more embodiments, the mesoporous material is selected from SBA-15, SBA- 22, MCM-41 , and modified mesoporous materials.

[0060] According to one or more embodiments, the particulate material component comprises a refractory metal oxide support material. As used herein, the term "refractory metal oxide" and refers to the underlying high surface area material upon which additional chemical compounds or elements are carried. The support particles have pores larger than 20 A and a wide pore distribution. In particular embodiments, high surface area refractory metal oxide supports can be utilized, e.g., alumina support materials, also referred to as "gamma alumina" or "activated alumina," which typically exhibit a BET surface area in excess of 60 square meters per gram ("m²/g"), often up to about 200 m²/g or higher. Such activated alumina is usually a mixture of the gamma and delta phases of alumina, but may also contain substantial amounts of eta, kappa and theta alumina phases. Refractory metal oxides other than activated alumina can be used as a support for at least some of the catalytic components in a given catalyst. For example, bulk ceria, zirconia, alpha alumina and other materials are known for such use. Although many of these materials suffer from the disadvantage of having a considerably lower BEI surface area than activated alumina, that disadvantage tends to be offset by a greater durability or performance enhancement of the resulting catalyst. "BET surface area" has its usual meaning of referring to the Brunauer, Emmett, Teller method for determining surface area by N₂ adsorption. Pore diameter and pore volume can also be determined using BET-type N₂ adsorption or desorption experiments.

[0061] One or more embodiments of the present invention include a high surface area refractory metal oxide comprising an activated compound selected from the group consisting of alumina, ceria, zirconia, silica, titania, silica-alumina, zirconia-alumina, titania-alumina, lanthana- alumina, lanthana-zirconia-alumina, baria-alumina, baria-lanthana-alumina, baria-lanthana- neodymia-alumina, alumina-chromia, alumina-ceria, zirconia-silica, titania-silica, or zirconia- titania, and combinations thereof. In one or more embodiments, the activated refractory metal oxide is exchanged with a metal selected from the group consisting of Cu, Fe, Co, Ni, La, Ce, Mn, V, Ag, and combinations thereof.

[0062] According to one or more embodiments, the particulate material component comprises a rare-earth oxide. As used herein, the term "rare earth oxide" refers to at least one oxide of a rare earth metal selected from yttria, ceria, lanthana, praseodymia, neodymia, and combinations thereof. In one or more embodiments, the rare earth oxide comprises ceria.

[0063] A further aspect of the invention is directed to a method of increasing the hydrophobicity of a material. In one or more embodiments, transformation of hydrophilic materials to hydrophobic materials can be achieved by impregnating a particulate material with a hydrophobic source (e.g. a fluorine component, a silica component, a siliconfluoride, polytetrafluoroethylene, hydrophobic silicone polymer), followed by calcination at elevated temperature, e.g. in a temperature range of about 150 to 550 °C. In particular embodiments, transformation of hydrophilic materials to hydrophobic materials can be achieved by impregnating a particulate material with a fluorine source, followed by calcination at elevated temperature, e.g. in a temperature range of about 150 to 550 °C. In a specific embodiment, the fluorine source is impregnated onto the oxide surface of a particulate material component, such as alumina, silica- alumina, zeolite (ZSM-5, SSZ-13, SSZ-62), PGM impregnated alumina, etc.

[0064] Without intending to be bound by theory, it is thought that the formation of hydrophobic sites can be applied in any reaction system where water competes with the active components over the sites. The method of increasing the hydrophobicity can be applied for any material where water or other hydrophobic materials will compete with hydrophilic materials. Thus, the method of increasing the hydrophobicity can be applied in a variety of situations, for example treatment of gasoline, diesel, and small engine exhaust streams, as well as for treatment/containment of oil spills and volatile organic compounds.

[0065] Transformation of hydrophilic materials into hydrophobic materials can also be achieved by an exchange procedure where the oxidic particulate material component, which is initially hydrophilic in nature, is mixed with the hydrophobic source (e.g. a fluorine component, a silica component, a siliconfluoride, polytetrafluoroethylene, hydrophobic silicone polymer) for about 30 minutes at temperatures up to 30-90 °C. In specific embodiments, transformation of hydrophilic materials into hydrophobic materials can be achieved by an exchange procedure where the oxidic particulate material component, which is initially hydrophilic in nature, is mixed with the fluorine source for about 30 minutes at temperatures up to 30-90 °C. After filtering and calcination at temperatures in the range of 150 °C to 550 °C, the hydrophobic materials show complete hydrophobicity. For example, these hydrophobic materials are able to extract octane from water at room temperature. In one or more embodiments, the fluorine source does not comprise a gas, and is selected from one or more of ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non-metal fluoride.

[0066] In U.S. Patent No. 4,297,335, zeolitic materials are contacted with fluorine gas to enhance the hydrophobicity of the zeolitic material. In the '335 patent, however, the direct fluorination of the zeolites not only modifies the zeolite surface, but also removes framework aluminum atoms; the zeolitic material is dealuminated in order to decrease the number of acid sites of the zeolitic material. In specific embodiments of the present invention, however, the method of increasing the hydrophobicity of a material is conducted such that dealumination of the material does not occur.

[0067] Transition metal (Cu or Fe) exchanged SAPO-34 is one of the molecular sieves used commercially for reducing NO_x in heavy duty diesel applications. Cu-chabazite and Cu-SAPO- 34 are two materials applied in selective catalytic reduction using urea as reductant. SAPO-34 is used by some as a substitute for Cu Chabazite; the reason for the use of SAPO-34 is due to its considerably lower cost than Cu Chabazite. However, due to its inferior durability in water compared to Cu-Chabazite, Cu-SAPO-34 requires special system calibration adjustments to minimize the impact of water from the exhaust on its durability. This approach however results in some fuel penalty. Without intending to be bound by theory, it is thought that one of the possible reasons for Cu-SAPO-34 deactivation is due to structure destabilization due to hydrolysis of the Si-O-P. Molecular water interacting with surface hydroxyl group leads to structure destabilization and separation of the silica from the P & alumina framework structure.

[0068] Accordingly, a second aspect of the invention is directed to a catalyst comprising an SCR component impregnated with a hydrophobic component. When impregnated with a hydrophobic component, the catalyst is effective to repel water from a surface of the SCR component. Specific embodiments are directed to a catalyst comprising an SCR component impregnated with a fluorine component. When impregnated with a fluorine component, the catalyst is effective to repel water from a surface of the SCR component. As used herein, the term "selective catalytic reduction" (SCR) refers to the catalytic process of reducing oxides of nitrogen to dinitrogen (N₂) using a nitrogenous reductant. In one or more embodiments, the SCR component comprises Cu-SAPO-34, CuTiAPSO, CuCHA, CuZSM-5, FeZSM-5, Cu Beta, or Fe Beta. In specific embodiments, the SCR component comprises Cu-SAPO-34, and the catalyst is effective to repel water from a surface of the Cu-SAPO-34 component.

[0069] One approach to minimize water destabilization of the structure is by creating a hydrophobic surface on the catalyst. In one or more embodiments, the catalyst surface (e.g. CuCHA, Cu-SAPO-34) is treated with NH4F solution. The oxide particulate material component (e.g. Cu-CHA, Cu-SAPO-34) was mixed with ammonium fluoride solution for about 30 minutes at temperatures up to 30-90 °C. After filtering and calcination, the materials showed complete hydrophobicity. These materials were able to extract octane from water at room temperature. [0070] Hydrophobic materials can be used in a variety of situations. Thus, an additional aspect of the invention is direct to a method. In one or more embodiments, the method comprises providing a material having a hydrophobic surface treatment selected from a hydrophobic component impregnated on a surface of the material and an oxide that minimizes water adsorption on the material surface, the hydrophobic surface treatment effective to repel one or more of water and a hydrophilic material from the surface of the material, and using the material having the hydrophobic surface treatment in an environment containing moisture. The hydrophobic surface treatment prevents moisture from interfering with the catalytic activity and/or sorption of the material. In one or more embodiments, the hydrophobic component is selected from a fluorine component, a silica component, a siliconfluoride, polytetrafluoroethylene, hydrophobic silicone polymer, and mixtures thereof. In specific embodiments, the hydrophobic component comprises a fluorine component.

[0071] In some embodiments, the material having the hydrophobic surface treatment can be used to remove a hydrocarbon contaminant from water or from an atmosphere containing water. For example, the material having the hydrophobic surface treatment can be used in an oil spill to separate the hydrophobic hydrocarbons from water. Thus, in one or more embodiments, the hydrocarbon is selected from an alkane having C2-C30 carbons and the material comprises one or more of a molecular sieve, alumina (silica-alumina), silica, clay, bentonite, montmorillonite, kaolinite, halloysite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, gibbsite (alumina trihydrate), boehmite, silica-magnesia, magnesia, and sepiolite.

[0072] In other embodiments, the material having the hydrophobic surface treatment can be used to remove volatile organic compounds from the ambient atmosphere, wherein the ambient atmosphere contains humidity. For example, the material having the hydrophobic surface treatment can be used to separate a volatile organic compound present in a gas phase containing water vapor.

[0073] In still further embodiments, the material having the hydrophobic surface treatment can be used to remove hydrocarbons from an engine exhaust stream. In such cases, the material comprises a molecular sieve or a mesoporous material which has a hydrophobic surface treatment. In specific embodiments, therefore, the material having the hydrophobic surface treatment functions as a hydrocarbon trap. [0074] In other embodiments, the method comprises reducing NO_x in the exhaust gas stream of a lean burn engine and the material comprises a base metal and a molecular sieve. Without in intending to be bound by theory, it is thought that HC and NO_x reduction during cold start can be improved by minimizing water competition with the NO and hydrocarbon over active sites such as Pd, Pvh, and Pt. In specific embodiments, the base metal comprises copper and the molecular sieve comprises SAPO-34.

[0075] In other aspects of the present invention, a fully formulated catalytic article (e.g. a catalytic material coated on a honeycomb substrate) is transformed into a hydrophobic material by treating the catalytic article with the hydrophobic surface treatment. Thus, in one or more embodiments, a catalytic article comprising a catalyst washcoated on a honeycomb, which is hydrophilic is transformed into a hydrophobic material by treating the formulated catalyst with a hydrophobic source (e.g. a fluorine component, a silica component, a siliconfluoride, polytetrafluoroethylene, hydrophobic silicone polymer, and mixtures thereof), followed by calcination at elevated temperature, e.g. in a temperature range of about 150 to 550 °C. In particular embodiments, transformation of hydrophilic formulated catalysts into hydrophobic formulated catalysts can be achieved by impregnating a formulated catalyst with a fluorine source, followed by calcination at elevated temperature. In one or more embodiments, the formulated catalyst can optionally comprise one or more platinum group metal.

[0076] The invention is now described with reference to the following examples. Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

EXAMPLES

[0077] Example 1 : Preparation of Hydrophobic Zeolite-Y: Ammonium fluoride (about 5g) was dissolved in water. The H-Y zeolite (about 10 g) was added to the solution while mixing. The temperature was increased to about 80 °C. In a covered container, the reaction was mixed at 80 °C for about 15 minutes. The mixture was then filtered, dried at 120 °C, followed by calcination at 450 °C. After cooling, the fluoride based zeolite showed flotation on water, indicating the formation of hydrophobicity. The material was coated on different surfaces/substrates. The hydrophobic material is used for adsorbing small levels of noxious hydrocarbon from a gas stream containing water vapor, such as the exhaust gas of gasoline and diesel engines.

[0078] Example 2: Preparation of Hydrophobic ZSM-5: Ammonium fluoride (about 5g) was dissolved in water. HZSM-5 zeolite (about 10 g) was added to the solution while mixing. The temperature was increase to about 80 °C. In a covered container, the reaction was mixed at 80 °C for about 15 minutes. The mixture was then filtered, dried, calcined solid at 120 °C, followed by calcination at 450 °C. After cooling, the fluoride based zeolite showed flotation on water, indicating the formation of hydrophobicity. The material was coated on different surfaces/substrates. The hydrophobic material is used for adsorbing small levels of noxious hydrocarbon from a gas stream containing water vapor, such as the exhaust gas of gasoline and diesel engines.

[0079] Example 3: Preparation of Hydrophobic Beta Zeolite: Hydrophobic Beta zeolite is prepared as in the procedure above. Ammonium fluoride (about 5g) is dissolved in water. H-Beta zeolite (about 10 g) is added to the solution while mixing. The temperature is increased to about 80 °C. In a covered container, the reaction is mixed at 80 °C for about 15 minutes. The mixture is then filtered, dried, calcined at 120 °C, followed by calcination at 450 °C. After cooling, the fluoride based zeolite shows flotation on water, indicating the formation of hydrophobicity. If desired, the material is coated on different surfaces/substrates. The hydrophobic material is used for adsorbing small levels of noxious hydrocarbon from a gas stream containing water vapor, such as the exhaust gas of gasoline and diesel engines.

[0080] Example 4: Preparation of Hydrophobic Silica-alumina: Hydrophobic silica-alumina was prepared by dissolving ammonium fluoride (about 5 g) in water. Silica alumina or clay (about 10 g) was added to the solution while mixing. The temperature was increased to about 80 °C. In a covered container, the reaction was mixed at 80 °C for about 15 minutes. The mixture was then filtered, dried, calcined at 120 °C, followed by calcination at 450 °C. After cooling, the fluoride based silica-alumina showed flotation on water, indicating the formation of hydrophobicity. If desired, the material was coated on different surfaces/substrates. The hydrophobic material is used for adsorbing small levels of noxious hydrocarbon from a gas stream containing water vapor, such as the exhaust gas of gasoline and diesel engines.

[0081] Example 5: Preparation of Hydrophobic alumina: The hydrophobic alumina was prepared by dissolving ammonium fluoride (about 5 g) in water. Alumina (about 10 g) was added to the solution while mixing. The temperature was increased to about 80 °C. In a covered container, the reaction was mixed at 80 °C for about 15 minutes. The mixture was then filtered, dried, calcined at 120 °C, followed by calcination at 450 °C. After cooling, the fluoride based alumina showed flotation on water, indicating the formation of hydrophobicity. If desired, the material is coated on different surfaces/substrates. This material may be used to selectively remove hydrophilic hydrocarbons from contaminated water, so this is used in oil spills where water may interfere with the cleaning process.

[0082] Example 6: Preparation of hydrophobic coated PGM type catalysts (Gasoline or diesel coated catalysts): This catalyst may contain hydrocarbon trap as one of the catalytic converter (Gasoline or Diesel). A slurry containing a PGM component is coated on a flow through or plug flow filter. The slurries can be applied in different designs. Examples of catalytic converters contacting hydrocarbon traps are known to those skilled in the art. After coating the hydrocarbon trap and the PGM catalyst onto the substrate, ammonium fluoride solution is applied by impregnation or by refluxing the coated catalyst in ammonium fluoride solution. The final catalytic converter is available as a hydrophobic coated catalyst. The hydrophobic coated catalyst is used in gasoline or diesel exhaust gas streams, where a hydrophobic hydrocarbon trap can be used to reduce hydrocarbon emissions from the exhaust gas stream during cold start. This will greatly enhance the hydrocarbon pickup in the presence of about 10% steam during vehicle cold start.

[0083] Example 7: Modification of metal exchanged zeolites, where liquid water can destroy the zeolite structure, rendering the material ineffective, is conducted as follows: Formation of Cu- SAPO-34 - Cu-SAPO-34 is known as an ammonia selective reduction catalyst. Unfortunately, the material (Cu-SAPO-34) collapses in the presence of water in the exhaust gas stream. Transforming this material (Cu-SAPO-34) into a hydrophobic material prevents the water from destroying the zeolite structure. Here, application of fluoride based materials is used to create hydrophobicity and prevent water adsorption and destruction of the zeolitic structure. One procedure is as described in other examples, where ammonium fluoride is applied. In other instances, a fluorine component obtained from a fluorine source comprising one or more of a fluorine gas, an organo fluoride, a metal fluoride salt, and a non-metal fluoride is applied. In still other instances, a silica component, a silicon fluoride, polytetrafluorethylene, or a hydrophobic silicone polymer is applied. [0084] Reference throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0085] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. A hydrophobic material for use as a catalyst or sorbent, the hydrophobic material comprising:

a particulate material component impregnated with a hydrophobic component, the hydrophobic material effective to repel one or more of water or a hydrophilic material from a surface of the particulate material component,

wherein the particulate material component comprises one or more of a molecular sieve, a metal oxide, a mixed metal oxide, a non-zeolitic material, a clay material, a rare- earth oxide, a mesoporous material, and an activated refractory metal oxide, wherein the hydrophobic material is effective as a sorbent or catalyst.

2. The hydrophobic material of claim 1, wherein the hydrophobic components is selected from one or more of a fluorine component, a silica component, a silicon fluoride, polytetrafluoroethylene, and a hydrophobic silicone polymer.

3. The hydrophobic material of claim 1 , wherein the hydrophobic component comprises a fluorine component.

4. The hydrophobic material of claim 3, wherein the fluorine component is not obtained from gaseous ammonium fluoride.

5. The hydrophobic material of claim 3, wherein the fluorine component is obtained from a fluorine source comprising one or more of fluorine gas, ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non-metal fluoride.

6. The hydrophobic material of claim 5, wherein the metal fluoride salt is selected from lithium fluoride (LiF), calcium difluoride (CaF₂), GpIA, GpIIA, hexafluorosilicic acid (SiF₆), phosphorus trifluoride (PF₃), fluorosilicic acid, A1F₃, BaF₂, CdF₂, CeF₂, Na₃AlF₆, HfFzt, LaF₃, PbF₂, MgF₂, KF, rare earth fluorides, NaF, TI1F4, yttrium barium fluoride, yttrium calcium fluoride, and combinations thereof.

7. The hydrophobic material of claim 5, wherein the fluorine source comprises ammonium fluoride solution.

8. The hydrophobic material of claim 5, wherein the organo fluoride is selected from CH₃F, CH2F2, CHF₃, CF4, fluoro ethane, fluoropropane, flourobutane, fluorohexanes, fluorobenzene, nafeon polymer, fluoroaromatic compounds, trifluoroacetic acid, and combinations thereof.

9. The hydrophobic material of claim 5, wherein the non-metal fluoride is selected from boron trifluoride (BF₃), phosphorus trifluoride (PF₃), HF, and combinations thereof.

10. The hydrophobic material of claim 1, wherein the molecular sieve has a structure type selected from the group consisting of MFI, BEA, AEI, AFT, AFX, CHA, EAB, EMT, ERI, FAU, GME, JSR, KFI, LEV, LTL, LTN, MOZ, MSO, MWW, OFF, SAS, SAT, SAV, SBS, SBT, SFW, SSF, SZR, TSC, WEN, and combinations thereof.

11. The hydrophobic material of claim 1 , wherein the molecular sieve is promoted with a metal selected from Pt, Pd, Rh, Ru, Ir, Cu, Fe, Co, Ni, La, Ce, Mn, V, Ag, and combinations thereof.

12. The hydrophobic material of claim 1 , wherein the non-zeolitic material is selected from kaolinite, halloysite, montmorillonite, bentonite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, clay, gibbsite (alumina trihydrate), boehmite, silica-magnesia, magnesia and sepiolite.

13. The hydrophobic material of claim 1 , wherein the mesoporous material is selected from SBA-15, SBA-22, MCM-41, and modified mesoporous materials.

14. The hydrophobic material of claim 1, wherein the hydrophobic material is selected from a catalyst or sorbent, or combinations thereof.

15. A catalyst comprising: an SCR component impregnated with a fluorine component, the catalyst effective to repel water from a surface of the SCR component.

16. The catalyst of claim 15, wherein the SCR component comprises Cu-SAPO-34, CuTiAPSO, CuCHA, CuZSM-5, FeZSM-5, Cu Beta, or Fe Beta.

17. A catalyst comprising:

a hydrocarbon trap component impregnated with a fluorine component, the catalyst effective to repel water from a surface of the hydrocarbon trap component.

18. A method comprising:

providing a material having a hydrophobic surface treatment selected from a fluoride impregnated on a surface of the material and an oxide that minimizes water adsorption on the material surface, the hydrophobic surface treatment effective to repel one or more of water and a hydrophilic material from the surface of the material;

using the material having the hydrophobic surface treatment in an environment containing moisture, wherein the material is used as one or more of a catalyst and a sorbent, and wherein the hydrophobic surface treatment prevents moisture from interfering with catalytic activity and/or sorption of the material.

19. The method of claim 18, wherein the method comprises removing a hydrocarbon contaminant from water.

20. The method of claim 19, wherein the hydrocarbon is selected from an alkane having C₂- C30 carbons and the material comprises one or more of a molecular sieve, alumina (silica- alumina), silica, clay, bentonite, montmorillonite, kaolinite, halloysite, attapulgite, kaolin, amorphous kaolin, metakaolin, mullite, spinel, hydrous kaolin, gibbsite (alumina trihydrate), boehmite, silica-magnesia, magnesia, and sepiolite.

21. The method of claim 18, wherein the method comprises removing volatile organic compounds from the ambient atmosphere, wherein the ambient atmosphere contains humidity.

22. The method of claim 18, wherein the method comprises removing hydrocarbons from an engine exhaust stream and the material comprises a molecular sieve or a mesoporous material.

23. The method of claim 18, wherein the method comprises reducing NO_x in the exhaust gas stream of a lean burn engine and the material comprises a base metal and a molecular sieve.

24. The method of claim 23, wherein the base metal comprises copper and the molecular sieve comprises SAPO-34.

25. A method of increasing the hydrophobicity of a material, the method comprising:

impregnating a material with a fluorine source;

calcining the impregnated material at about 150 to 550 °C;

wherein the material comprises one or more of a molecular sieve, a metal oxide, a mixed metal oxide, a non-zeolitic material, a clay material, a rare-earth oxide, a mesoporous material, and an activated refractory metal oxide;

with the proviso that the fluorine source does not comprise a gas.

26. The method of claim 25, wherein the fluorine source comprises one or more of ammonium fluoride, an organo fluoride, a metal fluoride salt, and a non-metal fluoride.

27. The method of claim 25, wherein dealumination of the material does not occur.