摘要:
A process for preparing a catalyst comprising a mixed metal oxide 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, involves vapor depositing one upon the other a plurality of thin films.
摘要:
Modified metal oxide catalysts, in particular Mo-V-Nb based catalysts, are disclosed. The processes for modifying the catalysts include treatment with a pyridine solution, refluxing in oxalic acid and methanol, and cryo-grinding. The utility of the modified catalysts in catalytic processes is described. Alkenes, unsaturated saturated carboxylic acids, saturated carboxylic acids and their higher analogues are prepared directly from corresponding alkanes, alkenes or alkanes and alkenes utilizing using one or more modified metal oxide catalysts.
摘要:
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 prepared by drying and calcining an admixture of the precursor compounds in presence of an NO x -source such as HNO 3 e.g. of Mo, V, Te and Nb.
摘要:
The present invention relates to mixed metal oxide (MMO1) catalysts. MMO1 catalyst performance is improved with a sub-monolayer deposition of Te onto its surface by vapor deposition. The selectivity to acrylic acid improved by approximately 6% and the acrylic acid yield by 3%, absolute. Applying a similar Te loading onto MMO1 by wet impregnation methods did not improve catalytic performance. Post treatment of the Te vapor deposited MMO1 catalyst with oxygen at elevated temperatures gave improved catalytic performance when compared to a corresponding sample treated with an inert gas at the same elevated temperatures.
摘要:
Improved processes for the preparation of olefins, unsaturated carboxylic acids and unsaturated nitriles involve the use of dehydrogenation catalysts suitable for the conversion of alkanes to alkenes and catalysts suitable for the conversion of alkanes and/or alkenes to unsaturated carboxylic acids or unsaturated nitriles.
摘要:
An improved catalyst comprising a mixed metal oxide is prepared by the use of a sol-gel technique. The mixed metal oxide catalyst comprising Mo, V, Te and Nb is prepared by admixing compounds of these elements and at least one solvent, preferably water, to form a gel, ageing said so-formed gel and calcining it. The catalyst is useful for the conversion of an alkane, or a mixture of an alkane and an alkene, to an unsaturated carboxylic acid by vapor phase oxidation, or to an unsaturated nitrile by vapor phase oxidation in the presence of ammonia.
摘要:
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 nitriles, 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.
摘要:
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. The catalyst comprises an element selected from the group consisting of Br, Cl, F and I.