A High Pressure Operando Spectroscopy Examination of Bimetal Interactions in ‘Metal Efficient’ Palladium/In₂O₃/Al₂O₃ Catalysts for CO₂ Hydrogenation

Abstract

CO2 hydrogenation to methanol has the potential to serve as a sustainable route to a wide variety of hydrocarbons, fuels and plastics in the quest for net zero. Synergistic Pd/In2O3 catalysts show high CO2 conversion and methanol selectivity, enhancing methanol yield. The identity of the optimal active site for this reaction is unclear, either as a Pd‐In alloy, proximate metals, or distinct sites. In this work, we demonstrate that metal‐efficient Pd/In2O3 species dispersed on Al2O3 can match the performance of pure Pd/In2O3 systems. Further, we follow the evolution of both Pd and In sites and surface species under operando reaction conditions using x‐ray absorption and infrared spectroscopy. In doing so, we can determine both the nature of the active sites and the influence on the catalytic mechanism.