Effect of Surface Cu0 Content of the Catalysts on CO2 Hydrogenation to C2+ Alcohols

Pyrolyzing metal organic framework (MOF) material Fe-MIL-88B loaded with Cu in air atmosphere, uniformly dispersed CuFe based catalysts with different Cu and Fe valence distribution were gained at different reduction temperatures. The structure of the catalysts were characterized by means of X-ray diffraction (XRD) , X-ray photoelectron spectroscopy(XPS) , H-2 temperature program reduction (H-2-TPR) , N-2 adsorption-desorption (BET) , scanning electron microscopy (SEM) , and high resolution transmission electron microscopy (HRTEM). The catalytic performances of CO2 hydrogenation to C2+ alcohols were investigated on a fixed-bed reactor. It was found that the higher the reduction temperature was , the more percentage of Cu and Fe with lower valence state was on the surface of the catalysts. When the reduction temperature was 350 degrees C , Cu-0/(Cu+ +Cu-0) was 73. 9 %, and 0. 4% Fe-0 appeared, the catalytic performance was the best, where the CO2 conversion rate was 6. 82% , the total alcohol selectivity was 39. 4% , and the molar percentage of C2+ alcohol was 95. 1%.