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 (C-2-C-6) 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 mu mol olefin/s/g(Fe)). 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.

Automated summary

FeCx catalysts were synthesized by co-pyrolyzing iron nitrate with various CN sources. The Fe-d-C3N4-(0.3)-Py catalyst exhibited the highest CO2 conversion, olefin yield, and olefin STY, attributed to its high surface FeCx concentration. A correlation between surface FeCx and hydrocarbon/olefin STY was established.