Surface structure-based CO2 reduction reaction modelling over supported copper catalysts

Abstract Reverse water gas shift (RWGS) is a promising green approach for CO2 capture and utilisation, which is able to valorise CO2 by reducing it to CO using hydrogen obtained via renewable electricity. Five different copper-based catalysts were synthesized – 10 wt. % Cu/M (M = Al2O3/CeO2/TiO2/SiO2/ZrO2). The catalysts were tested for activity under different conditions (pressure of 3–7 bars, temperature of 280–360 °C, 0.67–1.5 H2/CO2 reagent ratio and the gas flow rates in the range of 0.005–0.04 g/min). Cu/Al2O3 and Cu/CeO2 were the most active and reached near-equilibrium conversions at 360 °C. SEM, EDX, BET, XRD, XPS, HgP, H2 TPR, H2 TPD and N2O PSO techniques were used to characterise the catalysts. The present study is the first to demonstrate an unprecedented degree of linking the activity measurements, material surface-structure and mathematical modelling of mass transport phenomena coupled with copper microkinetics for the case of CO2 reduction.