Catalytic hydrogenation of CO2 to light olefins by using K-doped FeCx catalysts derived from the Fe-chitosan complex

K-doped FeCx catalysts derived from the carbothermal reduction of the Fe-chitosan complex were investigated and tested in the hydrogenation of CO2 to light olefins (C2-6=). Catalyst characterization, including bulk composition, porosity, crystallinity, Fe coordination, morphology, surface property, and basicity, was conducted. The physicochemical properties of tested catalysts were correlated with their performances. The mechanistic study discovered that bidentate carbonates, monodentate carbonate, bicarbonate, and formate species were intermediates involved in C2-6= synthesis. The yield of C2-6= was found to be dependent on the composition of the carbide phases of K-doped FeCx catalysts. The most active catalyst, i.e., FeK@CS-(0.5)-py, showed the most promising space-time yield of C2-6= (13.7 μmolC2-6=/gFe/s).