Electronically Activated Fe5C2 via N-Doped Carbon to Enhance Photothermal Syngas Conversion to Light Olefins

Solar-driven CO hydrogenation to light olefins holds great potential as a petroleum-independent process. Herein, a series of Fe5C2 loading on tunable N-doped carbon as photothermal catalysts are developed to achieve an efficient Fischer–Tropsch synthesis to olefin (FTO) reaction. Under light irradiation, the optimized catalyst delivers a selectivity of 55.3% for light olefins (CO2 free) at a CO conversion of 22.3%, showing 3.5 times the activity of pristine Fe5C2 catalyst. Experimental characterizations reveal electron transfer from the N atoms in support to the active phase of Fe5C2 to construct electron-rich active sites and therefore to boost the catalytic performance. N-concentration-dependent activity evaluation and density functional theory calculations ascertain that pyrrolic N plays a dominant role in promoting CO adsorption and activation. This study provides an alternative strategy of rational modulation of support to enhance solar-to-chemical conversion.