A catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt, comprising a) contacting an alkene and carbon dioxide with a carboxylation catalyst, an organic solvent, and an alkoxide having a secondary or tertiary carbon atom directly bound to an [O−] group, to obtain a crude reaction product comprising the α,β-ethylenically unsaturated carboxylic acid salt and an alcohol by-product which is the conjugate acid of the alkoxide, b) allowing the α,β-ethylenically unsaturated carboxylic acid salt to precipitate out from the crude reaction product; and c) subjecting at least part of the crude reaction product to a mechanical separation step while maintaining the alcohol by-product in liquid form to obtain a solid phase comprising the α,β-ethylenically unsaturated carboxylic acid salt and a liquid phase comprising the carboxylation catalyst, the organic solvent and the alcohol by-product. The process allows for easy separation of the α,β-ethylenically unsaturated carboxylic acid salt by a mechanical separation operation.