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

K-doped FeC_x catalysts derived from the carbothermal reduction of the Fe-chitosan complex were investigated and tested in the hydrogenation of CO₂ to light olefins (C_2-6⁼). 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 C_2-6⁼ synthesis. The yield of C_2-6⁼ was found to be dependent on the composition of the carbide phases of K-doped FeC_x catalysts. The most active catalyst, i.e., FeK@CS-(0.5)-py, showed the most promising space-time yield of C_2-6⁼ (13.7 μmol_C2-6=/g_Fe/s).