Abstract: In accordance with the present invention there is provided a novel catalyst system in which the catalytic structure is tailormade at the nanometer scale using the invention's novel ship-in-a-bottle synthesis techniques. The invention describes modified forms of solid catalysts for use in heterogeneous catalysis that have a microporous structure defined by nanocages. Examples include zeolites, SAPOs, and analogous materials that have the controlled pore dimensions and hydrothermal stability required for many industrial processes. The invention provides for modification of these catalysts using reagents that are small enough to pass through the windows used to access the cages. The small reagents are then reacted to form larger molecules in the cages.

Abstract: The invention relates to a process for producing alkylated aromatic hydrocarbons, preferably with an oxygen or sulfur containing alkylating agent, in the presence of a multi-component molecular sieve catalyst composition that includes a molecular sieve and an active metal oxide. The invention is also directed to methods of making and formulating the multi-component molecular sieve catalyst composition useful in producing alkylated aromatics.

Abstract: This invention is directed to a hardened molecular sieve catalyst composition, a method of making the composition and a method of using the composition. The catalyst composition is made by mixing together molecular sieve, liquid, and an effective hardening amount of a dried molecular sieve catalyst to form a slurry. The slurry is dried, and then calcined to form the hardened molecular sieve catalyst composition. The hardened molecular sieve catalyst is highly attrition resistant.

Abstract: In a method of synthesizing a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of an AEI framework type material and a CHA framework type material, a first synthesis mixture is prepared comprising water and sources of phosphorus, aluminum and optionally silicon. The first synthesis mixture is then heated under agitation to a first temperature to form an intermediate product mixture containing a silicoaluminophosphate or aluminophosphate precursor material. The intermediate product mixture is then cooled and stored at a second temperature lower than the first temperature, whereafter a second synthesis mixture is prepared comprising at least part of the intermediate product mixture and at least one organic directing agent. The second synthesis mixture is heated to a third temperature higher than the second temperature to convert at least part of the precursor material into the desired molecular sieve and the molecular sieve is recovered.

Abstract: The present invention relates to an improved process for the preparation of porous crystalline silicoaluminophosphate molecular sieves designated as SAPO-35. These molecular sieves are useful as catalysts in the transformation of hydrocarbons especially in the methanol to olefin reaction.

Abstract: The invention relates to a metallophosphate-type crystallized solid, referred to by the name IM-6, which exhibits an X-ray diffraction diagram as given below. This metallophosphate-type solid can be partially substituted by an element X and optionally by an element Y. Said metallophosphate exhibits a chemical composition, expressed on an anhydrous base, defined by the formula RS,(GgPpXxYy)O2, where G represents one or more trivalent element(s), R represents one or more organic compound(s), X represents one or more divalent element(s), Y represents one or more tetravalent element(s), and in which s?0.2, g?0.5, p?0.5, x?0.4, y?0.3, with g+p+x+y=1.

Abstract: A method for maintaining the activity of silicoaluminophosphate (SAPO) molecular sieve catalyst particles during oxygenate to olefin conversion reactions. After regeneration of SAPO catalyst particles, the regenerated particles are mixed with particles having coke on their surface in a manner that maintains their catalytic activity at a predetermined level.

Abstract: The invention relates to a molecular sieve catalyst composition, to a method of making or forming the molecular sieve catalyst composition, and to a conversion process using the catalyst composition. In particular, the invention is directed to a catalyst composition comprising a molecular sieve having a framework including at least [AlO4] and [PO4] tetrahedral units, at least one of a binder and a matrix material and at least one phosphorus compound separate from said molecular sieve wherein, after calcination at 760° C. for 3 hours, said catalyst composition has a microporous surface area in excess of 20% of the microporous surface area of said molecular sieve after calcination at 650° C. in nitrogen for 2 hours. The catalyst composition is particularly useful in a conversion process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.

Abstract: There is disclosed a production process for a catalyst which process makes it possible to efficiently carry out the supporting of a catalytic component onto a carrier and to obtain the catalyst excellent in quality and performance. This production process is a production process for the catalyst including a particulate lump carrier and a catalytic component supported thereon; with the production process comprising the step of carrying out simultaneous revolution and rocking of a treatment container 20 as charged with the carrier and a catalyst precursor including the catalytic component, thereby supporting the catalytic component onto the carrier.

Abstract: Disclosed is a method for the manufacture of silicoaluminophosphate (SAPO) and/or aluminophosphate (ALPO) molecular sieves. The method includes maintaining the slurry of the as crystallized molecular sieve under substantially static conditions when stored after substantially complete crystallization and prior to recovery of the product.

Abstract: The invention is directed to methods for protecting metalloaluminophosphate molecular sieves, particularly silicoaluminophosphate (SAPO) molecular sieves, from loss of catalytic activity due to contact with a gas containing water. The methods of the invention provide procedures that enable activated sieve to contact water vapor, within a certain range of time, temperature, and water partial pressure conditions, before the sieve becomes substantially deactivated.

Abstract: The invention relates to a catalyst composition, a method of making the same and its use in the conversion of a feedstock, preferably an oxygenated feedstock, into one or more olefin(s), preferably ethylene and/or propylene The catalyst composition comprises a molecular sieve and at least one oxide of a metal selected from Group 3 of the Periodic Table of Elements, the Lanthanide series of elements and the Actinide series of elements.

Abstract: Colloidal crystalline molecular sieve seeds are used in phosphorus-containing crystalline molecular sieve manufacture. Certain of the products have enhanced utility in oxygenate conversions.

Abstract: The present invention relates to a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of molecular sieves having AEI and CHA framework types, wherein said intergrown phase has an AEI/CHA ratio of from about 5/95 to 40/60 as determined by DIFFaX analysis, using the powder X-ray diffraction pattern of a calcined sample of said silicoaluminophosphate molecular sieve. It also relates to methods for its preparation and to its use in the catalytic conversion of methanol to olefins.

Abstract: The invention relates to a catalyst composition, a method of making the same and its use in the conversion of a feedstock, preferably an oxygenated feedstock, into one or more olefin(s), preferably ethylene and/or propylene The catalyst composition a molecular sieve, such as a silicoaluminophosphate and/or an aluminophosphate, hydrotalcite, and optionally a rare earth metal component

Abstract: Novel zeolites are produced by combining a polar solute, a silicon or phosphorous source, and a structure directing agent. Surfactants and a hydrophobic solvent are added to the previously mixed three species and shaken to disperse the surfactants. The reverse microemulsion is stirred overnight, at about room temperature and then iced for five to ten minutes. A metal source is added vigorously shaken for about two minutes. The mixture is then aged for about two hours at about room temperature. A mineralizer is added and the resultant mixture aged for about two hours at about room temperature. The mixture is heated to about 180° C., for a suitable time period. The final novel product is then isolated.

Abstract: The invention is directed to a method for modifying a microporous metalloaluminophosphate molecular sieve, the method comprising the steps of a) introducing a compound containing at least one M-X group within the cages of said microporous molecular sieve; and b) reacting said compound containing at least one M-X group with the acid groups located in the cages of the molecular sieve, wherein the compound containing at least one M-X group is selected from the group consisting of compounds of formula MX3, compounds of formula M2X6, and mixtures thereof, M being a metal belonging to Group 13 of the Periodic Table, and each X independently being a hydrogen or halogen atom. Preferably, X is a hydrogen atom. The present invention also relates to modified metalloaluminophosphate molecular sieves, preferably modified silicoaluminophosphate molecular sieves, as well as to the use of these modified molecular sieves in catalytic processes, such as processes for the conversion of oxygenated hydrocarbon feedstocks.

Abstract: The present invention is directed to a process for preparing a catalyst which comprises combining catalyst components or precursors thereof in an aqueous medium to form a catalyst precursor mixture, feeding the mixture to a shaping apparatus, and shaping the mixture to form particles wherein just before the shaping step the mixture is destabilized. It was found that with this process catalysts can be prepared which have both a good attrition resistance and a high accessibility. The invention further relates to catalysts obtainable by this process.

Abstract: The invention is directed to a method of synthesising silicoaluminophosphate molecular sieves and in particular those of framework type CHA and AEL. The method uses synthesis templates that comprise one or more tertiary dialkylbutylamines, wherein the alkyl groups are not butyl. The use of such templates. especially N,N-dimethylbutylamine, results in SAPO-11 of a desirable platelet morphology.

Abstract: A catalyst composition suitable for reacting hydrocarbons, e.g., conversion processes such as fluidized catalytic cracking (FCC) of hydrocarbons, comprises attrition resistant particulate having a high level (30-85%) of stabilized zeolites having a constraint index of 1 to 12. The stabilized zeolite is bound by a phosphorous compound, alumina and optional binders wherein the alumina added to make the catalyst is about 10% by weight or less and the molar ratio of phosphorous (P2O5) to total alumina is sufficient to obtain an attrition index of about 20 or less. The composition can be used as a catalyst per se or as additive catalyst to a conventional catalyst and is especially suitable for enhancing yields of light olefins, and particularly ethylene, produced during conversion processes.

Abstract: The invention is directed to a method of stabilizing metalloaluminophosphate molecular sieves and catalysts derived therefrom. In particular, the invention is directed to a method of treating such molecular sieves with one or more nitrogen containing compounds having a kinetic diameter greater than the average pore size of the activated molecular sieve and selected from the group consisting of amines, monocyclic heterocyclic compounds, organonitrile compounds and mixtures thereof to chemisorbed and/or physisorbed the compound onto the molecular sieve. The compounds may be easily desorbed before or during use and after storage. The invention is also directed to formulating the molecular sieve into a catalyst useful in a process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.

Abstract: The invention is directed to a method of synthesizing silicoaluminophosphate molecular sieves using synthesis templates that contain at least one dimethylamino moiety, selected from one or more of N,N-dimethylethanolamine, N,N-dimethylpropanolamine, N,N-dimethylbutanolamine, N,N-dimethylheptanolamine, N,N-dimethylhexanolamine, N,N-dimethylethylenediamine, N,N-dimethylbutylenediamine, N,N-dimethylheptylenediamine, N,N-dimethylhexylenediamine 1-dimethylamino-2-propanol, N,N-dimethylethylamine, N,N-dimethylpropylamine, N,N-dimethylpentylamine, N,N-dimethylhexylamine and N,N-dimethylheptylamine. The use of dimethylamino moiety containing templates results in good quality SAPO molecular sieves of CHA framework type.

Abstract: The present invention concerns a method for enhancing the activity of vanadium phosphorus oxide (VPO) catalysts. Promoter reagents are grafted onto or reacted with the catalyst surface. An optional calcination and activation heating cycle transforms the catalyst precursor into a final active phase. A preferred VPO catalyst produced has a ratio of molybdenum to vanadium on the surface of the catalyst to molybdenum to vanadium in the overall bulk of the catalyst represented by the equation (Mo/V) Surface?1.10 (Mo/V) overall bulk.

Abstract: Disclosed is a method of protecting the loss of catalytic activity of metalloaluminophosphate molecular sieve, particularly a SAPO molecular sieve, from contact with moisture. The method involves heating the metalloaluminophosphate molecular sieve so as to remove template, and provide a molecular sieve in sufficiently dry form for storage.

Abstract: The invention is directed to a method of stabilizing metalloaluminophosphate molecular sieves and catalysts derived therefrom. In particular, the invention is directed to a method of treating such molecular sieves with chemisorbed ammonia, which may be easily desorbed before or during use and after storage. The invention is also directed to formulating the molecular sieve into a catalyst useful in a process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.

Abstract: Provided is a catalyst formulation which exhibits extended catalyst life. The formulation comprises a mixture of a ceramic foam material uniformly interspersed between the solid catalyst particles, with the volume percent of ceramic material in the mixture preferably ranging from 20 to 60 volume %. The catalyst formulation is particularly applicable to solid catalyst particles comprised of a phosphoric acid impregnated substrate, and is particularly useful for processes such as catalytic hydrocarbon condensation processes.

Abstract: What is claimed is a dealuminated catalyst carrier, a process for producing a catalyst carrier with reduced aluminum content based on naturally occurring lattice-layer silicates, such as, for example, montmorillonite, as well as a process for the hydration reaction of C2- or C3-olefins in which said catalyst carrier with reduced aluminium content is used. For acid-catalysed hydration reaction the catalyst carrier is impregnated with phosphoric acid. The improvements according to the invention of the hydration reaction compared to conventional processes include the fact that no aluminium is leached out of the carrier in the presence of the phosphoric acid. As a result no more blockage of the succeeding apparatus due to aluminium phosphate is expected.

Abstract: The invention relates to a molecular sieve catalyst composition, to a method of making or forming the molecular sieve catalyst composition, and to a conversion process using the catalyst composition. In particular, the invention is directed to a making a molecular sieve catalyst composition by forming a slurry by combining a molecular sieve, a binder and a matrix material, wherein the slurry has a pH, above or below the isoelectric point of the molecular sieve. The catalyst composition has improved attrition resistance, particularly useful in a conversion process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.

Abstract: A process for preparing a catalyst for maleic anhydride production wherein a +5 vanadium compound such as V2O5, an anhydrous phosphoric acid, and optionally promoters are admixed in an organic alcohol solvent, the admixture is rapidly brought to reflux and thereafter refluxed to reduced the vanadium compound to the desired degree, the reflux mixture is cooled, precursor crystals are separated by filtration and then dried and calcined.

Abstract: A process for the preparation of hydrotreating catalyst which comprises of a Group VIB metal and Group VIII metal on an active composite carrier for the removal of sulfur from gas oil feed stocks, wherein the said carrier comprises of a phosphated alumina and an ultra stable Y zeolite and the metal components mostly reside on the alumina, said process comprising the steps of impregnation of chelated metal complex preferentially on to the alumina component of the composite support and subjecting the composite catalyst to a high-speed ball milling. The catalyst obtained by the process of the present invention consists of the active metals in the nanoparticle range (less than 50 ?) while also retaining the zeolite properties of the composite carrier and the catalyst produces less than 50 ppm sulfur from gas oil feed stocks containing greater than 1 wt % sulfur under typical commercial operating conditions.

Abstract: The present invention relates to a process for the production of a titanium silicalite shaped body by: (a) forming a formable composition containing titanium silicalite, a binder and a pasting agent, so that the Curd curve of the formable composition has a plateau value in the range from 20 to 90 mm; (b) shaping the composition of step (a) to form a green body; (c) optionally drying and (d) calcining the green body, to a titanium silicalite shaped body obtainable by that process, and to the use of such titanium silicalite shaped bodies in the epoxidation of olefins or the ammoximation of ketones.

Abstract: The invention relates to a catalyst composition, a method of making the same and its use in the conversion of a feedstock, preferably an oxygenated feedstock, into one or more olefin(s), preferably ethylene and/or propylene. The catalyst composition comprises a molecular sieve and at least one oxide of a metal from Group 4, optionally in combination with at least one metal from Groups 2 and 3, of the Periodic Table of Elements.

Abstract: The present invention concerns a method for the production of a titanium-containing zeolite whereby a synthesis gel is formed by combining and hydrolysing a hydrolysable silicon compound, a hydrolysable titanium compound and a basic quaternary ammonium compound in an aqueous medium, in quantities such that relative to the starting compounds the molar ratio of Si/Ti is greater than or equal to 30 and that of N/Si is 0.12 to less than 0.20, and the synthesis gel is then crystallised at a temperature of 150 ° C. to 220 ° C. for a period of less than 3 days, and a titanium-containing zeolite obtainable by this method.

Abstract: This invention is directed to a molecular sieve composition or a catalyst containing molecular sieve which has a relatively high residual silica index, preferably at least about 1.5. The molecular sieve or catalyst can be made by contacting a template-containing molecular sieve with a silicon containing material having an average kinetic diameter that is larger than the average pore diameter of the sieve or catalyst, and heating to leave residual silica at the sieve or catalyst surface. The molecular sieve or catalyst is particularly effective in making an olefin product from an oxygenate feedstock.

Abstract: The invention relates to a molecular sieve catalyst composition, to a method of making or forming the molecular sieve catalyst composition, and to a conversion process using the catalyst composition. In particular, the invention is directed to making a formulated molecular sieve catalyst composition from a slurry of formulation composition of a synthesized molecular sieve that has not been fully dried, a binder and an optional matrix material. In a more preferred embodiment, the weight ratio of the binder to the molecular sieve and/or the solid content of the slurry is controlled to provide an improved attrition resistant catalyst composition, particularly useful in a conversion process for producing olefin(s), preferably ethylene and/or propylene, from a feedstock, preferably an oxygenate containing feedstock.

Abstract: EMM-3 (ExxonMobil Material number 3) is a new crystalline microporous material with a framework of tetrahedral atoms connected by atoms capable of bridging the tetrahedral atoms, the tetrahedral atom framework being defined by the interconnections between the tetrahedrally coordinated atoms in its framework. EMM-3 can be prepared in aluminophosphate (AlPO) and metalloaluminophosphate (MeAPO) compositions with the hexamethonium template. It has a unique X-ray diffraction pattern, which identifies it as a new material. EMM-3 is stable to calcination in air, absorbs hydrocarbons, and is catalytically active for hydrocarbon conversion.

Abstract: The invention is directed to a method of synthesizing aluminophosphate and silicoaluminophosphate molecular sieves and in particular to the synthesis of aluminophosphate and silicoaluminophosphate molecular sieves using the synthesis templates that contain two dimethylamino moieties in combination with hydrogen fluoride. The use of this template in combination with hydrogen fluoride results in good quality SAPO molecular sieves of CHA framework type with low levels of silicon that are produced in relatively short crystallization times.

Abstract: The invention is directed to methods for protecting metalloaluminophosphate molecular sieves, particularly silicoaluminophosphate (SAPO) molecular sieves, from loss of catalytic activity due to contact with a gas containing water. The methods of the invention provide procedures that enable activated sieve to contact water vapor, within a certain range of time, temperature, and water partial pressure conditions, before the sieve becomes substantially deactivated.

Abstract: A structure directing agent is removed from a microporous solid at a temperature below the temperature that would cause the structure directing agent to decompose by cleaving the structure directing agent within the pores of the microporous solid, at a temperature below the temperature that would cause the structure directing agent to decompose, into two or more fragments and removing the fragments from the pores of the microporous solid at a temperature below the temperature that would cause the structure directing agent or its fragments to decompose.

Abstract: Disclosed is a method of protecting the loss of catalytic activity of metalloaluminophosphate molecular sieve, particularly a SAPO molecular sieve, from contact with moisture. The method involves heating the metalloaluminophosphate molecular sieve so as to remove template, and provide a molecular sieve in sufficiently dry form for storage.

Abstract: The invention is directed to a method of synthesising silicoaluminophosphate and aluminophosphate molecular sieves using synthesis templates that contain at least one template of general formula R1R2N—R3, wherein R1 and R2 are independently selected from the group consisting of alkyl groups having from 1 to 3 carbon atoms and hydroxyalkyl groups having from 1 to 3 carbon atoms; R3 is selected from the group consisting of 4- to 8-membered cycloalkyl groups, optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms, and 4- to 8-membered heterocyclic groups having from 1 to 3 heteroatoms, said heterocyclic groups being optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms and the heteroatoms in said heterocyclic groups being selected from the group consisting of O, N, and S. In particular, the present invention relates to the synthesis of silicoaluminophosphate molecular sieves of the CHA framework type having a low silicon to aluminium atomic ratio.

Abstract: This invention is directed to a hardened molecular sieve catalyst composition, a method of making the composition and a method of using the composition. The catalyst composition is made by mixing together molecular sieve, liquid, and an effective hardening amount of a dried molecular sieve catalyst to form a slurry. The slurry is dried, and then calcined to form the hardened molecular sieve catalyst composition. The hardened molecular sieve catalyst is highly attrition resistant.

Abstract: A method for the post synthesis modification of molecular sieves with organometallic reagents. The method may be used for large pore molecular sieves and small pore molecular sieves, such as SAPO-34. SAPO-34 is a useful catalyst for the conversion of oxygenates, such as methanol, to olefins. Post synthesis organometallic modification improves catalyst performance and increases light olefin selectivity in the conversion of methanol to olefins.

Abstract: The invention is directed to a method for modifying a microporous metalloaluminophosphate molecular sieve, the method comprising the steps of a) introducing a metal hydride compound within the cages of said microporous molecular sieve, and b) reacting said metal hydride compound with the acid groups located in the cages of the molecular sieve, wherein the metal hydride compound is selected from the group consisting of hydrides of metals of Groups 1 and 2 of the Periodic Table, compounds of formula M1M2H4 and mixtures thereof, M1 being a metal belonging to Group 13 of the Periodic Table and M2 being a metal belonging to Group 1 of the Periodic Table. The invention also relates to modified metalloaluminophosphate molecular sieves, to catalyst particles containing them and the use of the modified metalloaluminophosphate molecular sieves in catalytic processes.

Abstract: The present invention relates to a silicoaluminophosphate molecular sieve comprising at least one intergrown phase of molecular sieves having AEI and CHA framework types, wherein said intergrown phase has an AEI/CHA ratio of from about 5/95 to 40/60 as determined by DIFFaX analysis, using the powder X-ray diffraction pattern of a calcined sample of said silicoaluminophosphate molecular sieve. It also relates to methods for its preparation and to its use in the catalytic conversion of methanol to olefins.

Abstract: Disclosed are methods and compositions of synthesis mixtures for the synthesis of aluminophosphates and silicoaluminophosphate molecular sieves, which enable the control and adjustment of the crystal particle size of aluminophosphates and silicoaluminophosphate molecular sieves. The synthesis mixture compositions used have two or more organic templates present at a molar ratio of total template to aluminum of ≦1.25; such a synthesis mixture is susceptible to control of product particle size through variation in the amount of seeds used in the synthesis.

Abstract: A new method for preparing lithium phosphate catalysts is disclosed. The method comprises precipitating a lithium phosphate from a mixture comprising a first aqueous solution which contains lithium and sodium ions and a second aqueous solution which contains phosphate and borate ions. The resultant lithium phosphate catalyst has increased activity and selectivity in the isomerization of an alkylene oxide to the corresponding allylic alcohol.

Abstract: This invention is directed to a method of making an olefin product from an oxygenate feedstock and a method of protecting catalytic activity of a silicoaluminophosphate molecular sieve. The methods comprise providing a silicoaluminophosphate molecular sieve having catalytic sites within the molecular sieve; shielding the catalytic sites to protect from loss of catalytic activity; and contacting the protected sieve in its activated state with an oxygenate feedstock under conditions effective to produce an olefin product before undesirable loss of catalytic activity. Undesirable loss in catalytic activity occurs when activated molecular sieve contacting the oxygenate feedstock has a methanol uptake index of at least 0.15.

Abstract: The invention is directed to a method for preparing microporous aluminophosphate or silicoaluminophosphate molecular sieves having the CHA framework type, the process comprising the steps of a) forming a reaction mixture comprising a source of aluminum, a source of phosphorus, optionally a source of silicon, at least one source of fluoride ions and at least one template containing one or more N,N-dimethylamino moieties, b) inducing crystallization of aluminophosphate and/or silicoaluminophosphate molecular sieve from the reaction mixture; c) recovering aluminophosphate and/or silicoaluminophosphate molecular sieve from the reaction mixture. The invention also relates to the molecular sieves obtained by this method and to molecular sieve catalyst compositions containing these molecular sieves.

Abstract: The present invention relates to a process for the selective preparation of acetic acid from a gaseous feed comprising ethane, ethylene or mixtures thereof plus oxygen at elevated temperature, which comprises bringing the gaseous feed into contact with a catalyst comprising the elements Mo, Pd, X and Y in gram atom ratios a:b:c:d in combination with oxygen MoaPdbXcYd??(I) where the symbols X and Y have the following meanings: X is one or more elements selected from the group consisting of: Cr, Mn, Nb, Ta, Ti, V, Te and/or W, in particular Nb, V and W; Y is one or more elements selected from the group consisting of: B, Al, Ga, In, Pt, Zn, Cd, Bi, Ce, Co, Cu, Rh, Ir, Au, Ag, Fe, Ru, Os, K, Rb, Cs, Mg, Ca, Sr, Ba, Zr, Hf, Ni, P, Pb, Sb, Si, Sn, TI and U, in particular Ca, Sb, Te and Li. The present invention further provides a catalyst for the selective preparation of acetic acid comprising the elements Mo, Pd, X and Y in the gram atom ratios a:b:c:d in combination with oxygen.