Provided is a catalyst article comprising a substrate and a catalyst composition disposed on the substrate, the catalyst composition comprising a support material having supported thereon: one or more platinum group metals (PGMs); and a Ta-polyoxometalate (POM).

The present invention provides an oxygen evolution reaction catalyst, wherein the oxygen evolution reaction catalyst is an oxide material comprising iridium and tantalum: wherein the oxygen evolution reaction catalyst comprises a crystalline oxide phase having the rutile crystal structure: wherein the crystalline oxide phase has a lattice parameter a of greater than 4.510 ?; and wherein the oxygen evolution reaction catalyst has a BET surface area of at least 50 m.sup.2/g.

A photocatalytic member comprises a base and a photocatalytic layer fixed on the base. The photocatalytic layer comprises first photocatalyst particles being visible light responsive photocatalyst particles for hydrogen generation, second photocatalyst particles being visible light responsive photocatalyst particles for oxygen generation, and conductive particles which are provided between the first photocatalyst particle and the second photocatalyst particle, have Fermi level at a negative position relative to an electronic energy level at the upper end of the valence band of the first photocatalyst particle and at a positive position relative to an electronic energy level at the bottom end of the conduction band of the second photocatalyst particle, and are able to store an electron and a hole. In the photocatalytic layer, the conductive particles are located to be coupled to both the first photocatalyst particles and the second photocatalyst particles.

A method of operating a fuel cell having an anode, a cathode and a polymer electrolyte membrane disposed between the anode and the cathode, includes feeding the anode with an impure hydrogen stream having low levels of carbon monoxide up to 5 ppm, and wherein the anode includes an anode catalyst layer including a carbon monoxide tolerant catalyst material, wherein the catalyst material includes: (i) a binary alloy of PtX, wherein X is a metal selected from the group consisting of rhodium and osmium, and wherein the atomic percentage of platinum in the alloy is from 45 to 80 atomic % and the atomic percentage of X in the alloy is from 20 to 55 atomic %; and (ii) a support material on which the PtX alloy is dispersed; wherein the total loading of platinum group metals (PGM) in the anode catalyst layer is from 0.01 to 0.2 mgPGM/cm.sup.2.

A method of operating a fuel cell having an anode, a cathode and a polymer electrolyte membrane disposed between the anode and the cathode, includes feeding the anode with an impure hydrogen stream having low levels of carbon monoxide up to 5 ppm, wherein the anode includes an anode catalyst layer including a carbon monoxide tolerant catalyst material, wherein the catalyst material includes: (i) a binary alloy of PtX, wherein X is a metal selected from the group consisting of Nb and Ta, and wherein the atomic percentage of platinum in the alloy is from 45 to 80 atomic % and the atomic percentage of X in the alloy is from 20 to 55 atomic %; and (ii) a support material on which the PtX alloy is dispersed; wherein the total loading of platinum in the anode catalyst layer is from 0.01 to 0.2 mgPt/cm.sup.2.

A method of operating a fuel cell having an anode, a cathode and a polymer electrolyte membrane disposed between the anode and the cathode, includes feeding the anode with an impure hydrogen stream having low levels of carbon monoxide up to 5 ppm, and wherein the anode includes an anode catalyst layer including a carbon monoxide tolerant catalyst material, wherein the catalyst material includes: (i) a binary alloy of PtX, wherein X is a metal selected from the group consisting of rhodium and osmium, and wherein the atomic percentage of platinum in the alloy is from 45 to 80 atomic % and the atomic percentage of X in the alloy is from 20 to 55 atomic %; and (ii) a support material on which the PtX alloy is dispersed; wherein the total loading of platinum group metals (PGM) in the anode catalyst layer is from 0.01 to 0.2 mgPGM/cm.sup.2.

A binary alloy catalyst comprising platinum and tantalum, wherein the tantalum is present in the alloy at 15 to 50 atomic % and a phosphoric acid fuel cell comprising such a catalyst is disclosed. The catalyst provides a better CO tolerance.

A catalyst comprising a platinum group metal (group 10) supported on a carrier, said carrier comprising a silica core and a precipitate layer of comprising a metal oxide, sulfate or phosphate on said core; said catalyst also comprising a rhodium group metal (group 9) supported on said carrier.

An exhaust gas purifying catalyst has enhanced NOx purification performance in a lean atmosphere, and a production method for producing an exhaust gas purifying catalyst includes sputtering a target material containing Ta and Rh to form composite fine metal particles respectively containing Ta and Rh.

Niobia- and tantala-doped ceria catalysts, their use in selective catalytic reduction (SCR) processes, and a compact after-treatment system for exhaust gases are disclosed. In some aspects, the catalyst comprises at least 91 wt. % of ceria and 0.1 to 9 wt. % of niobia or tantala doped on the ceria. While conventional SCR catalysts can deactivate at higher temperatures, the doped cerias, particularly ones having as little as 1 or 2 wt. % of Nb.sub.2O.sub.5 or Ta.sub.2O.sub.5, are activated toward NOx conversion by calcination. The doped cerias are also valuable for SCRF catalyzed filter applications, including an after-treatment system that comprises a diesel particulate filter having inlets and outlets, and a dual-function catalyst coated on the inlets, outlets, or both. Compared with conventional SCR catalysts, the niobia or tantala-doped cerias enable a higher level of NO.sub.2 to be present.