This disclosure provides for routes of synthesis of α,β-unsaturated carboxylic acids and their salts, including acrylic acid. For example, disclosed is a process for producing an α,β-unsaturated carboxylic acid or its salt, comprising: (1) contacting a group 8-11 transition metal precursor, an olefin, carbon dioxide, a diluent, and a sulfur oxoacid anion-substituted polyaromatic resin or a phosphorus oxoacid anion-substituted polyaromatic resin with associated metal cations to provide a mixture; and (2) applying reaction conditions to the mixture suitable to produce the α,β-unsaturated carboxylic acid or a salt thereof. Methods of regenerating the polyaromatic resin with associated metal cations are described.