| abstract |
The present invention relates to a process for preparing an ethylenically unsaturated carboxylic acid or an ethylenically unsaturated carboxylic acid ester, preferably an α, β-ethylenically unsaturated carboxylic acid or an α, β-ethylenically unsaturated carboxylic acid ester. . The process involves contacting formaldehyde or a suitable source material with a carboxylic acid or ester in the presence of a catalyst, optionally in the presence of an alcohol. The catalyst comprises a nitrided metal oxide having at least two types of metal cations, M 1 and M 2 , where M 1 represents groups 2, 3, 4, 13 ( Selected from metals of Group IIIA) or Group 14 (also referred to as Group IVA) and M 2 is selected from metals of Group 5 or 15 (also referred to as Group VA) of the Periodic Table . The invention also extends to a catalyst system. |