Indirect methanol synthesis from CO₂ through high-efficient dimethyl carbonate hydrogenation as a bridge below 100°C.

Abstract

Developing an energy-efficient process to convert chemically inert CO₂ to methanol is of great significance in sustainable chemistry. Herein, we report an indirect pathway for methanol synthesis below 100 °C, utilizing CO₂-derived dimethyl carbonate (DMC) as a bridging molecule. By engineering oxygen vacancies in In₂O₃, we construct a Lewis acidic combination of In₅ sites and In₄…In_{4 ּ}pairs that efficiently activate H₂ and DMC, respectively. The spatial intimacy of In₅ and In₄…In₄ enables efficient transfer of generated *H, achieving a methanol generation rate of 31.6 mmol _ּg_cat^-1 h^-1 with >99.99% selectivity at 100 °C. Integrating DMC synthesis from CO₂ with subsequent hydrogenation in a single reactor via alternating feedstreams from CO₂ to H₂, the optimized In₂O₃ catalysts yield a methanol production rate of 5.2 mmol _ּg_cat^-1 h^-1 at 100 °C, outperforming the performance of previous catalysts through direct CO₂ hydrogenation even at temperatures over 200 °C.