Cu–Al Spinel as a Highly Active and Stable Catalyst for the Reverse Water Gas Shift Reaction

Abstract

The reverse water gas shift reaction is considered to be a highly attractive catalytic route for CO₂ recycling in a future sustainable economy. Copper-based catalysts are commonly used for this reaction due to their high activity and selectivity. However, their low thermal stability is problematic for long-term usage. Here, we introduce an in situ formed surface Cu–Al spinel as a highly active and stable catalyst for the reverse water gas shift reaction. Even at high weight hourly space velocities (300 000 mL g^–1 h^–1), we observed no detectable deactivation after 40 h of operation. Through in situ DRIFTS and DFT studies, it was found that 2-fold coordinated copper ions and 3-fold coordinated surface oxygen atoms constitute the active sites for this reaction.