Abstract:
Non-noble metal transition metal catalysts can replace platinum in the oxidation reduction reaction (ORR) used in electrochemical fuel cells. A RuxSe catalyst is prepared with comparable catalytic activity to platinum. An environmentally friendly aqueous synthetic pathway to this catalyst is also presented. Using the same aqueous methodology, ORR catalysts can be prepared where Ru is replaced by Mo, Fe, Co, Cr, Ni and/or W. Similarly Se can be replaced by S.
Abstract:
A novel method for preparing a heteropolyacid catalyst containing a heteropolyacid composed of molybdophosphoric acid and/or molybdovanadophosphoric acid, or a salt of the heteropolyacid, is provided. The method comprises preparing an aqueous solution or aqueous dispersion which (1) contains the nitrogen-containing heterocyclic compound, nitrate anions and ammonium ions, (2) the ammonium ion content not exceeding 1.7 mols per mol of the nitrate anion content, and (3) the ammonium ion content not exceeding 10 mols per 12 mols of the molybdenum atom content by mixing raw materials containing the catalyst-constituting elements with the nitrogen-containing heterocyclic compound in the presence of water, drying and calcining the same. This heteropolyacid catalyst excels over conventional catalysts in performance, life and strength.
Abstract:
A catalyst comprising a promoted mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.
Abstract:
A mixed metal oxide, which may be an orthorhombic phase material, is improved as a catalyst for the production of unsaturated carboxylic acids, or unsaturated nitrites, from alkanes, or mixtures of alkanes and alkenes, by contact with a liquid contacting member selected from the group consisting of organic acids, alcohols, inorganic acids and hydrogen peroxide.
Abstract:
A process for preparing a metal oxide catalyst for acrylic acid production which comprises calcining a metal compound mixture at 400null C. or higher to prepare a metal oxide powder comprising Mo, V, Sb, and at least one element selected from the group consisting of Nb and Ta, and supporting a compound comprising at least one element selected from the group consisting of Sb, Tl, Se, As, Pb, Sn, Ag, Cu, Ru, and Rh on the metal oxide powder, and a process for producing acrylic acid by gas phase oxidation of propane using the catalyst.
Abstract:
A catalyst suitable for the gas-phase oxidation of organic compounds to null,null-unsaturated aldehydes and/or carboxylic acids and having an active phase comprising a multimetal oxide material is prepared by a process in which a particulate catalyst precursor which contains oxides and/or compounds of the elements other than oxygen which constitute the multimetal oxide material, which compounds can be converted into oxides, is prepared and said catalyst precursor is converted by calcination into a catalytically active form, wherein a stream of the particulate catalyst precursor is passed at substantially constant speed through at least one calcination zone at constant temperature for calcination.
Abstract:
A catalyst comprising a mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile. The catalyst is treated with a source of hydrogen, an alcohol, a source of NOx or a mixture thereof.
Abstract:
A mixed metal oxide, which may be an orthorhombic phase material, is improved as a catalyst for the production of unsaturated carboxylic acids, or unsaturated nitrites, from alkanes, or mixtures of alkanes and alkenes, by: contacting with a liquid contact member selected from the group consisting of organic acids, alcohols, inorganic acids and hydrogen peroxide to form a contact mixture; recovering insoluble material from the contact mixture; calcining the recovered insoluble material in a non-oxidizing atmosphere; admixing the calcined recovered insoluble material with (i) at least one promoter element or compound thereof and (ii) at least one solvent for the at least one promoter element or compound thereof; removing the at least one solvent to form a catalyst precursor; and calcining the catalyst precursor.