Spectroscopy-guided optimization of copper-based catalysts for low-temperature CO2 recycling to CO

Abstract

The reverse water–gas shift (RWGS) reaction provides a sustainable route for CO₂ valorization by producing CO, a key intermediate for various industrial applications. Its endothermic nature and the competition with Sabatier reaction impose a practical challenge on the design of low and medium temperature RWGS catalysts thus hampering its integration with downstream units. In this study, we investigate the design and optimization of Cu-based materials for low-temperature RWGS. A series of Cu/TiO₂ catalysts were synthesized and characterized using operando UV-vis, DRIFTS, and NAP-XPS spectroscopies. These studies allow us to prioritize the most promising catalyst and to derive key insights into surface intermediates, such as the formation of acrolein as a major coke precursor. These insights enable us to optimize the catalyst and mitigate deactivation through coking. Pt doping is shown to be particularly effective in reducing coke deposition, thus enhancing the long-term stability and overall catalyst's performance. Our multicomponent PtCuK@ catalyst demonstrated superior activity, selectivity, and regenerability under extended operation, opening new horizons for advanced RWGS catalysts targeting industrial CO₂ utilization. This work also provides a comprehensive framework for enhancing catalyst durability and anti-coking strategies in sustainable CO₂ valorization processes.