The purpose of the present invention is to provide a zirconia-based composite oxide for making it possible to form a catalyst layer which, despite having a reduced thickness, has a sufficient quantity of catalyst to function in exhaust gas treatment on a wall of a honeycomb structure. The purpose of the present invention is also to provide a method for manufacturing said zirconia-based composite oxide. The present invention relates to a zirconia-based composite oxide characterized in that the tap bulk density thereof is 0.75 g/mL or greater, and the specific surface area thereof after heat treatment for three hours at 1000° C. is 45 m.sup.2/g or greater.

The invention relates to a catalyst comprising a support, at least one noble metal M, tin, phosphorus and yttrium, the content of phosphorus element being less than or equal to 1% by weight, and the content of yttrium being less than or equal to 1% by weight relative to the mass of the catalyst. The invention also relates to the process for preparing the catalyst and to the use thereof in reforming.

The invention relates to a catalyst comprising a support, at least one noble metal M, tin, phosphorus and yttrium, the content of phosphorus element being less than or equal to 1% by weight, and the content of yttrium being less than or equal to 1% by weight relative to the mass of the catalyst. The invention also relates to the process for preparing the catalyst and to the use thereof in reforming.

Disclosed are novel catalyst compositions, catalyst precursors, processes for making catalyst precursors, processes for making catalyst compositions, and processes for converting syngas. The catalytic component in the catalyst composition can comprise a metal carbide and/or a metal nitride. This disclosure is particularly useful for converting syngas via the Fischer-Tropsch reactions to make olefins and/or alcohols.

Disclosed are novel catalyst compositions, catalyst precursors, processes for making catalyst precursors, processes for making catalyst compositions, and processes for converting syngas. The catalytic component in the catalyst composition can comprise a metal carbide and/or a metal nitride. This disclosure is particularly useful for converting syngas via the Fischer-Tropsch reactions to make olefins and/or alcohols.

A Ce—Zr composite oxide contains cerium and zirconium, wherein an uneven distribution ratio of cerium atoms is 1.80 or less. A method for producing a Ce—Zr composite oxide includes an acid treatment step of bringing at least one selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid, in an amount of 4 to 28 parts by mass with respect to 100 parts by mass of the raw material composite oxide, into contact with the surface of a raw material composite oxide containing cerium and zirconium, and a calcination step of calcining the treated composite oxide obtained in the acid treatment step at 400 to 1200° C. for 5 to 300 minutes.

A Ce—Zr composite oxide contains cerium and zirconium, wherein an uneven distribution ratio of cerium atoms is 1.80 or less. A method for producing a Ce—Zr composite oxide includes an acid treatment step of bringing at least one selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid, in an amount of 4 to 28 parts by mass with respect to 100 parts by mass of the raw material composite oxide, into contact with the surface of a raw material composite oxide containing cerium and zirconium, and a calcination step of calcining the treated composite oxide obtained in the acid treatment step at 400 to 1200° C. for 5 to 300 minutes.

Bifunctional catalyst compositions, methods, and systems are provided for the use of CO.sub.2 as a soft oxidizing agent to effectively convert low-value small alkanes to high-value small olefins. The bifunctional catalyst comprises a metal oxide catalyst and a redox-active ceramic support.

Bifunctional catalyst compositions, methods, and systems are provided for the use of CO.sub.2 as a soft oxidizing agent to effectively convert low-value small alkanes to high-value small olefins. The bifunctional catalyst comprises a metal oxide catalyst and a redox-active ceramic support.

High surface area, high entropy oxides comprising multiple metal cations in a single-phase fluorite lattice material enables intrinsic catalytic activity without platinum group metals, tunable oxygen storage capacity, and thermal stability. These properties can be obtained through a facile sol-gel synthesis to provide a low-temperature route for production of phase-pure multi-cationic oxides. The resulting materials achieved significantly higher surface area and catalytic performance, taking advantage of all the properties endowed by the various cations in the composition.