Efficient Ni-based catalysts for low-temperature reverse water-gas shift (RWGS) reaction

Abstract

CO₂ hydrogenation for syngas can alleviate the pressure of un-controlled emissions of CO₂ and bring enormous economic benefits. Advantageous Ni-catalysts have good CO₂ hydrogenation activity and high CO selectivity merely over 700 °C. Herein, we introduced Cu into Ni catalysts, which were evaluated by H₂ -TPR, XRD, BET, in-situ XPS and CO₂ -TPD, and their CO₂ hydrogenation activity and CO selectivity were significantly affected by the Ni/Cu ratios, which was rationalized by the synergistic effect of bimetallic catalysts. In addition, the reduction temperatures of studied catalysts apparently affected the CO₂ hydrogenation, which were caused by the number and dispersion of the active species. It's found that the Ni₁ Cu₁ -400 had good stability, high CO selectivity (up to 90%), and fast formation rate (1.81×10^-5 mol/g_cat /s) at 400 °C, which demonstrated a good potential as a superior catalyst for reverse water-gas shift (RWGS) reaction.

Keywords: CO2 hydrogenation; Effect of reduction temperature; Ni-Cu bimetallic catalyst; RWGS reaction; synergistic effect.