A three-way catalyst article, and its use in an exhaust system for compressed natural gas engines, is disclosed. The catalyst article for treating exhaust gas from compressed natural gas (CNG) engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first PGM component; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second PGM component; wherein the first PGM component comprises palladium, platinum, or a combination thereof; and wherein the second PGM component comprises rhodium.

A method for producing a catalyst for unsaturated carboxylic acid synthesis is proposed. The method includes: obtaining a dried product by drying and heat-treating a starting material mixed liquid in which supply source compounds of respective catalyst component elements are integrated; and forming a catalyst precursor by supporting powder to be supported on a carrier in the form of a particle aggregate. The powder to be supported is either the dried product or obtained from the dried product. The method further includes calcining the catalyst precursor to form the catalyst. The mass loss rate of the powder to be supported at 300° C. is less than 5 percent by mass, and the difference between the mass loss rate of the powder at 370° C. and the mass loss rate of the powder at 300° C. is not less than 1 percent by mass and not more than 6 percent by mass.

A method for producing a catalyst for unsaturated carboxylic acid synthesis is proposed. The method includes: obtaining a dried product by drying and heat-treating a starting material mixed liquid in which supply source compounds of respective catalyst component elements are integrated; and forming a catalyst precursor by supporting powder to be supported on a carrier in the form of a particle aggregate. The powder to be supported is either the dried product or obtained from the dried product. The method further includes calcining the catalyst precursor to form the catalyst. The mass loss rate of the powder to be supported at 300° C. is less than 5 percent by mass, and the difference between the mass loss rate of the powder at 370° C. and the mass loss rate of the powder at 300° C. is not less than 1 percent by mass and not more than 6 percent by mass.

A catalyst comprising a carrier and a metals component impregnated in the carrier, the carrier comprising alumina; and the metals component comprising a first metals fraction and a second metals fraction, the first metals fraction comprising at least one metal selected from chromium, molybdenum, or tungsten, and the second metals fraction comprising at least two metals selected from cobalt, rhodium, iridium, nickel, palladium, or platinum, wherein the catalyst has a first pore volume of 0.28 to 0.45 mL/g for pores having a pore diameter of 12 nm to less than 16 nm, and a second pore volume of 0.15 to 0.28 mL/g for pores of 2.0 nm to less than 12.0 nm.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; a first catalytic region comprising a first platinum group metal (PGM) component supported on a first PGM support material, wherein the first PGM component comprises platinum and rhodium; and wherein the first PGM support material comprises ZrO.sub.2—Al.sub.2O.sub.3.

A perovskite-type oxide catalyst for water-splitting reactions is provided. The catalyst, Ca.sub.2-ySr.sub.yFe.sub.1-xCo.sub.1-xMn.sub.2xO.sub.6-δ where y=0.10-1.90 and x=0.05-0.95, has catalytic activity for both hydrogen- and oxygen-evolution reactions. An exemplary catalyst is CaSrFe.sub.0.75Co.sub.0.75Mn.sub.0.5O.sub.6-δ.

A perovskite-type oxide catalyst for water-splitting reactions is provided. The catalyst, Ca.sub.2-ySr.sub.yFe.sub.1-xCo.sub.1-xMn.sub.2xO.sub.6-δ where y=0.10-1.90 and x=0.05-0.95, has catalytic activity for both hydrogen- and oxygen-evolution reactions. An exemplary catalyst is CaSrFe.sub.0.75Co.sub.0.75Mn.sub.0.5O.sub.6-δ.

Provided is a composition comprising alumina, the alumina being surface-modified with a perovskite type compound of formula (I); wherein formula (I) is defined by A.sub.x-yA′.sub.yB.sub.1. .sub.zB′.sub.zO.sub.3; where: A is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; A′ is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; B is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; B′ is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; x is from 0.7 to 1; y is from 0 to 0.5; and z is from 0 to 0.5.

Provided is a composition comprising alumina, the alumina being surface-modified with a perovskite type compound of formula (I); wherein formula (I) is defined by A.sub.x-yA′.sub.yB.sub.1. .sub.zB′.sub.zO.sub.3; where: A is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; A′ is an ion of a metal selected from the group consisting of Li, Na, K, Cs, Mg, Sr, Ba, Ca, Y, La, Ce, Pr, Nd, and Gd; B is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; B′ is an ion of a metal selected from the group consisting of Cu, Mn, Mo, Co, Fe, Ni, Cr, Ti, Zr, Al, Ga, Sc, Nb, V, W, Bi, Zn, Sn, Pt, Rh, Pd, Ru, Au, Ag, and Ir; x is from 0.7 to 1; y is from 0 to 0.5; and z is from 0 to 0.5.

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.