Highly selective hydrogenation of CO2 to C5+ hydrocarbons over Fe catalysts copromoted by K with Pd

CO 2 hydrogenation to liquid fuels is significant to reduce CO 2 emissions and replace fossil fuels . Herein, we reported that Fe catalysts promoted by combination of K and Pd showed a three-synergistic catalytic effect to high selectivity of C 5+ hydrocarbons in CO 2 hydrogenation reaction. The catalysts were prepared using an impregnation method and characterized with physical adsorption , XRD , XPS , HRTEM , H 2 -TPR, H 2 -TPD and CO 2 -TPD. The results indicated that K 0.016 Pd 0.12 Fe catalysts showed K-overlapped PdFe-like alloy structure which enhanced H 2 activation behaviors and moderately chemisorption of CO 2 . K addition promoted Fe to activate carbide species while active H originated from H 2 pool generated by PdFe alloy spilled to Fe species surface, consequently boosting not only conversion of CO 2 to 41.8% but also selectivity of C 5+ hydrocarbon to 70.6%. The maximum yield of long-chain C 5+ hydrocarbon reached up to 20.0% under high space velocity 6000 mL g cat −1 h −1 . These results provide a new insight to develop highly selective Fe based catalysts for long-chain hydrocarbons via CO 2 hydrogenation.