A cerium-zirconium based mixed oxide composition have: (a) a Ce:Zr molar ratio of 1 or less, and (b) a cerium oxide content of 10-50% by weight. The composition has (i) a surface area of at least 18 m.sup.2/g, and a total pore volume as measured by N.sub.2 physisorption of at least 0.11 cm.sup.3/g, after ageing at 1100° C. in an air atmosphere for 6 hours, (ii) a surface area of at least 42 m.sup.2/g, and a total pore volume as measured by N.sub.2 physisorption of at least 0.31 cm.sup.3/g, after ageing at 1000° C. in an air atmosphere for 4 hours, and (iii) Dynamic Oxygen Storage Capacity (D-OSC) value as measured by H.sub.2-TIR of greater than 500 μmol/g at 600° C. after aging at 800° C. in an air atmosphere for 2 hours. A process contacts the exhaust gas with the composition Another process is for preparing the composition.

A cerium-zirconium based mixed oxide composition have: (a) a Ce:Zr molar ratio of 1 or less, and (b) a cerium oxide content of 10-50% by weight. The composition has (i) a surface area of at least 18 m.sup.2/g, and a total pore volume as measured by N.sub.2 physisorption of at least 0.11 cm.sup.3/g, after ageing at 1100° C. in an air atmosphere for 6 hours, (ii) a surface area of at least 42 m.sup.2/g, and a total pore volume as measured by N.sub.2 physisorption of at least 0.31 cm.sup.3/g, after ageing at 1000° C. in an air atmosphere for 4 hours, and (iii) Dynamic Oxygen Storage Capacity (D-OSC) value as measured by H.sub.2-TIR of greater than 500 μmol/g at 600° C. after aging at 800° C. in an air atmosphere for 2 hours. A process contacts the exhaust gas with the composition Another process is for preparing the composition.

In an exhaust gas purification catalyst, a catalytic component (100) containing a first oxide (21), a second oxide (22), and a precious metal (30) is supported on a three-dimensional structure (10); the ratio of the amount of precious metal (30) supported on the first oxide (21) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22), or the ratio of the amount of precious metal (30) supported on the second oxide (22) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22) is 70% or more to 100% or less, as measured by an electron probe microanalyzer (EPMA); and the amount of carbon monoxide that the precious metal (30) can adsorb per unit mass is 15 mL/g or more to 100 mL/g or less.

In an exhaust gas purification catalyst, a catalytic component (100) containing a first oxide (21), a second oxide (22), and a precious metal (30) is supported on a three-dimensional structure (10); the ratio of the amount of precious metal (30) supported on the first oxide (21) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22), or the ratio of the amount of precious metal (30) supported on the second oxide (22) to the total amount of precious metal (30) supported on the first oxide (21) and precious metal (30) supported on the second oxide (22) is 70% or more to 100% or less, as measured by an electron probe microanalyzer (EPMA); and the amount of carbon monoxide that the precious metal (30) can adsorb per unit mass is 15 mL/g or more to 100 mL/g or less.

Disclosed herein are 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 rare earths other than cerium and yttrium The compositions exhibit a particle size characterized by a Dso value of about 20 μm to about 45 μm and a D.sub.99 value of about 55 μm to about 1 00 μm. Further disclosed are processes of producing these compositions using oxalic acid in the process. The compositions can be used as a catalyst and/or part of a catalytic system for automobile exhaust gas.

Disclosed herein are 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 rare earths other than cerium and yttrium The compositions exhibit a particle size characterized by a Dso value of about 20 μm to about 45 μm and a D.sub.99 value of about 55 μm to about 1 00 μm. Further disclosed are processes of producing these compositions using oxalic acid in the process. The compositions can be used as a catalyst and/or part of a catalytic system for automobile exhaust gas.

The invention relates to a catalyst composition suitable for the dehydrogenation of paraffins having 2-8 carbon atoms comprising zinc oxide and titanium dioxide, optionally further comprising oxides of cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm), terbium (Tb), ytterbium (Yb), yttrium (Y), tungsten (W) and Zirconium (Zr) or mixtures thereof, wherein said catalyst composition is substantially free of chromium and platinum. The catalysts possess unique combinations of activity, selectivity, and stability. Methods for preparing improved dehydrogenation catalysts and a process for dehydrogenating paraffins having 2-8 carbon atoms, comprising contacting the mixed metal oxide catalyst with paraffins are also described. The catalyst may also be disposed on a porous support in an attrition-resistant form and used in a fluidized bed reactor.

The invention relates to a catalyst composition suitable for the dehydrogenation of paraffins having 2-8 carbon atoms comprising zinc oxide and titanium dioxide, optionally further comprising oxides of cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm), terbium (Tb), ytterbium (Yb), yttrium (Y), tungsten (W) and Zirconium (Zr) or mixtures thereof, wherein said catalyst composition is substantially free of chromium and platinum. The catalysts possess unique combinations of activity, selectivity, and stability. Methods for preparing improved dehydrogenation catalysts and a process for dehydrogenating paraffins having 2-8 carbon atoms, comprising contacting the mixed metal oxide catalyst with paraffins are also described. The catalyst may also be disposed on a porous support in an attrition-resistant form and used in a fluidized bed reactor.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al203, Si02, Fe02, Ti02, Zn02, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.

The invention relates to a wall-flow filter as a particle filter with catalytically active coatings in the channels which are closed in a gas-tight manner at the opposing closed ends of the channels A at the first end, wherein the inlet region of the filter is additionally supplied with a dry powder-gas aerosol which contains metal compounds with a high melting point (such as the metal oxides Al203, Si02, Fe02, Ti02, Zn02, etc. for example) and which is to simultaneously improve the catalytic activity and the degree of filtration efficiency with respect to the exhaust gas back-pressure.