This invention relates to azirconium hydroxideor zirconium oxide comprising, on an oxide basis, up to 30 wt % of a dopant comprising one or more of silicon, sulphate, phosphate, tungsten, niobium, aluminium, molybdenum, titanium or tin, and having acid sites, wherein the majority of the acid sites are Lewis acid sites. In addition, the invention relates to a catalyst, catalyst support or precursor, binder, functional binder, coating or sorbent comprising the zirconium hydroxide or zirconium oxide. The invention also relates to a process for preparing zirconium hydroxide, the process comprising the steps of:(a) dissolving a zirconium salt in an aqueous acid, (b) addingone or more complexing agents to the resulting solution or sol, the one or more complexing agents being an organic compound comprising at least one of the following functional groups: an amine, an organosulphate, a sulphonate, a hydroxyl, an ether or a carboxylic acid group, (c) heating the solution or sol formed in step (b), (d) adding a sulphating agent, and (e) adding a base to form a zirconium hydroxide, and (f) optionally adding a dopant.

A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer for storing nitrogen oxides (NOx) under lean exhaust gas conditions and releasing and/or reducing stored NOx during rich exhaust gas conditions, and a second layer, said second layer comprising a first zone for oxidizing carbon monoxide (CO) and/or hydrocarbons (HC), and a second zone for oxidizing nitric oxide (NO), and a substrate having an inlet end and an outlet end.

A lean NO.sub.x trap catalyst and its use in an emission treatment system for internal combustion engines is disclosed. The lean NO.sub.x trap catalyst comprises a first layer for storing nitrogen oxides (NOx) under lean exhaust gas conditions and releasing and/or reducing stored NOx during rich exhaust gas conditions, and a second layer, said second layer comprising a first zone for oxidizing carbon monoxide (CO) and/or hydrocarbons (HC), and a second zone for oxidizing nitric oxide (NO), and a substrate having an inlet end and an outlet end.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A nitrous oxide (N.sub.2O) removal catalyst composite is provided, comprising a N.sub.2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H.sub.2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H.sub.2-TPR). Methods of making and using the same are also provided.

A catalyst composition, suitable for producing ethylene and other C.sub.2+ hydrocarbons, from methane. The composition comprises a blended product of two distinct catalyst components, blended at such synergistic proportions that results in a catalyst having high ethylene selectivity while maintaining low ethyne selectivity and sufficient catalytic activity rate. The invention further provides a method for preparing such a catalyst composition and a process for producing ethylene and other C.sub.2+ hydrocarbons, using such a catalyst composition.

A catalyst composition, suitable for producing ethylene and other C.sub.2+ hydrocarbons, from methane. The composition comprises a blended product of two distinct catalyst components, blended at such synergistic proportions that results in a catalyst having high ethylene selectivity while maintaining low ethyne selectivity and sufficient catalytic activity rate. The invention further provides a method for preparing such a catalyst composition and a process for producing ethylene and other C.sub.2+ hydrocarbons, using such a catalyst composition.

A multilayer supported oxidative coupling of methane (OCM) catalyst composition (alpha-Al.sub.2O.sub.3 support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x/alpha-Al.sub.2O.sub.3; A is alkaline earth metal; Z is first rare earth element; E is second rare earth element; D is redox agent/third rare earth element; the first, second, third rare earth element are not the same; a=1.0; b=0.1-10.0; c=0.1-10.0; d=0-10.0; x balances oxidation states; first single oxide layer (Z.sub.b1O.sub.x1, b1=0.1-10.0; x1 balances oxidation states) contacts alpha-Al.sub.2O.sub.3 support and one or more mixed oxide layers; one or more mixed oxide layers (A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2, a2=1.0; b2=0.1-10.0; c2=0.1-10.0; d2=0-10.0; x2 balances oxidation states; A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x and A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2 are different) contacts first single oxide layer and optionally second single oxide layer, and second single oxide layer (AO), when present, contacts one or more mixed oxide layers and optionally first single oxide layer.

A multilayer supported oxidative coupling of methane (OCM) catalyst composition (alpha-Al.sub.2O.sub.3 support, first single oxide layer, one or more mixed oxide layers, optional second single oxide layer) characterized by formula A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x/alpha-Al.sub.2O.sub.3; A is alkaline earth metal; Z is first rare earth element; E is second rare earth element; D is redox agent/third rare earth element; the first, second, third rare earth element are not the same; a=1.0; b=0.1-10.0; c=0.1-10.0; d=0-10.0; x balances oxidation states; first single oxide layer (Z.sub.b1O.sub.x1, b1=0.1-10.0; x1 balances oxidation states) contacts alpha-Al.sub.2O.sub.3 support and one or more mixed oxide layers; one or more mixed oxide layers (A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2, a2=1.0; b2=0.1-10.0; c2=0.1-10.0; d2=0-10.0; x2 balances oxidation states; A.sub.aZ.sub.bE.sub.cD.sub.dO.sub.x and A.sub.a2Z.sub.b2E.sub.c2D.sub.d2O.sub.x2 are different) contacts first single oxide layer and optionally second single oxide layer, and second single oxide layer (AO), when present, contacts one or more mixed oxide layers and optionally first single oxide layer.

Disclosed herein are mixed oxide compositions comprising zirconium and cerium having a surprisingly small particle sizes. The compositions disclosed herein contain zirconium, cerium, optionally yttrium, and optionally one or more other rare earths other than cerium and yttrium. The compositions exhibit a particle size characterized by a D90 value of about 5 um to about 25 μm and a D99 value of about 5 μm to about 50 μm. Further disclosed are processes of producing these compositions using oxalic acid and an alcohol and heating in the process. The compositions can be used as a catalyst and/or part of an automobile exhaust system.