PII.136 Correlating metal speciation and product selectivity during CO2 hydrogenation over Pd/CeO2 catalyst

Resumo

This study investigates palladium speciation on Pd/CeO₂ catalysts and its impact on CO₂ hydrogenation at high pressure. DRIFT spectroscopy was employed to monitor Pd speciation changes using CO as a probe molecule. Calcination temperature influences the distribution of single Pd^δ+ species and Pd⁰-containing nanoparticles. Isolated Pd^δ+ atoms enhance the rWGS reaction by weakening CO adsorption and suppressing H₂ dissociation. The control of Pd^δ+ and Pd⁰ fractions improved methanol productivity at low temperatures. Enhanced CO₂ conversion rates occur with atomic dispersion. This work offers a protocol for Pd dispersion control and highlights its correlation with product distribution during the reaction.