Maleic anhydride production using thallium-vanadium modified phosphotungstic catalysts
US4143056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1977 |
| Grant date | Mar 6, 1979 |
| Priority date | — |
| Expiry date | Nov 21, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C51/252
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A lower unsaturated aliphatic hydrocarbon of at least 4 carbon atoms and an oxygen-containing gas react to form maleic anhydride in the presence of a catalyst having the oxides of tungsten, phosphorus, thallium, and vanadium, said catalyst being a phosphotungstic catalyst modified by minor amounts of thallium oxide and vanadium oxide, the sum of the oxides of Tl and V constituting from 1% to 15% of the catalyst, the atom ratio of Tl:V being within a range from about 2:1 to about 8:1 and the overall atomic ratios are such that W:P:Tl:V corresponds to 1:0.1-0.7:0.01-0.16:0.01-0.1. Sometimes from about 3 to about 50 volume percent steam is added to the reactant stream to enhance catalyst stability and selectivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.