Boosting light olefin selectivity in CO2 hydrogenation by adding Co to Fe catalysts within close proximity

Direct conversion of carbon dioxide (CO 2 ) into lower olefins (C 2 -C 4 = ) is highly attractive as a sustainable production route for its great significance in greenhouse gas emission control and fossil fuel substitution. Fe-based catalysts have been extensively studied in CO 2 hydrogenation, which usually show unsatisfactory selectivity toward lower olefins. Here we present a high-dispersion catalyst precursor CoFe 2 O 4 with Na (Na-CoFe 2 O 4 ) that offers C 2 -C 4 = space time yield as high as 2.88 μmol C2-C4= g cat −1 s -1 and olefin to paraffin ratio about 6 at CO 2 conversion higher than 41 %. High dispersion and the intimate contact between Fe and Co sites help inhibit the formation of methane, and favor a higher selectivity of C 2 + hydrocarbons, especially lower olefins. The presence of Na further promotes chain growth and suppresses the direct hydrogenation of Fe-(CH 2 ) n intermediates. A superior stability over 100 h was observed, demonstrating the promising potential of this catalyst for industrial applications.