Conversion of CO2 to Light Hydrocarbons by Using FeCx Catalysts Derived from Iron Nitrate Co-pyrolyzing with Melamine, Bulk g-C3N4, or Defective g-C3N4.

FeCx catalysts (Fe-CN-Py) were synthesized by co-pyrolyzing the mixture of iron nitrate and a CN source (melamine, bulk g-C3N4 (b-C3N4), or defective g-C3N4 (d-C3N4)). The physicochemical properties of Fe-CN-Py catalysts and their activities of CO2 hydrogenation to light hydrocarbon (C2-C6) were analyzed. The results indicated that Fe-d-C3N4-(0.3)-Py is the most promising with the highest CO2 conversion (47.2%), olefin yield (10.8%), and olefin space-time yield (STY = 4.5 µmol olefin/s/gFe). The promising activity of Fe-d-C3N4-(0.3)-Py was attributed to its high concentration of surface FeCx. The correlation between surface FeCx and the STY of hydrocarbons and olefins was established. [ABSTRACT FROM AUTHOR]