An exhaust gas-purifying catalyst includes a support and a catalytic metal supported thereby. The support includes a composite oxide represented by AO.xB.sub.2-C.sub.O.sub.3, wherein A represents at least one of an element having a valence of 1 and an element having a valence of 2, B represents an element having a valence of 3, C represents one or more elements selected from iridium, ruthenium, tantalum, niobium, molybdenum, and tungsten, x represents a numerical value of 1 to 6, and a represents a numerical value greater than 0 and less than 2. The catalytic metal includes one or more precious metals selected from rhodium, palladium, and platinum.

Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.

Hydroxypropionic acid, hydroxypropionic acid derivatives, or mixtures thereof are dehydrated using a catalyst and a method to produce bio-acrylic acid, acrylic acid derivatives, or mixtures thereof. A method to produce the dehydration catalyst is also provided.

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.

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.

The present invention provides an oxygen evolution reaction catalyst, wherein the oxygen evolution reaction catalyst is an oxide material comprising iridium, tantalum and ruthenium: wherein the oxygen evolution 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 .

The present invention provides an oxygen evolution reaction catalyst, wherein the oxygen evolution reaction catalyst is an oxide material comprising iridium, tantalum and ruthenium: wherein the oxygen evolution 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 .

Shaped catalyst compositions and methods for making and using the shaped catalyst compositions are provided. In an exemplary a catalyst active phase includes a MoVTeTaOx catalyst. The composition also includes a support phase, wherein the support phase includes fumed silica, and wherein the catalyst active phase and support phase form a heterogeneous mixture.

A catalyst, useful for oxidative dehydrogenation of ethane, comprising molybdenum, vanadium, tellurium, tantalum, and oxygen, prepared using a stage hydrothermal synthesis procedure, is provided. The catalyst comprises from 30 to 50 wt. % amorphous content and may be combined with a support/carrier material to form a catalyst material. The described catalysts and catalyst materials demonstrate high selectivity for ethylene at higher temperatures, show little to no decline in conversion and selectivity over time, and do not appear to be sensitive to low residual oxygen concentrations.