Title：Molecular Iridium Complexes in Metal-Organic Frameworks Catalyze CO2 Hydrogenation via Concerted Proton and Hydride Transfer

Authors: Bing An, Lingzhen Zeng, Mei Jia, Zhe Li, Zekai Lin, Yang Song, Yang Zhou, Jun Cheng, Cheng Wang, and Wenbin Lin

Abstract:

Molecular iridium catalysts immobilized in metal-organic frame-works (MOFs) were positioned in the condensing chamber of a Soxhlet extractor for efficient CO₂ hydrogenation. Droplets of hot water seeped through the MOF catalyst to create dynamic gas/liquid interfaces which maximize the contact of CO₂, H₂, H₂O, and the catalyst to achieve a high turnover frequency of 410 h^-1 under atmospheric pressure and at 85 ^oC. H/D kinetic isotope effect measurements and density functional theory calculations revealed concerted proton-hydride transfer in the rate-determining step of CO₂ hydrogenation, which was difficult to unravel in homogeneou reactions due to base-catalyzed H/D exchange.

Full-Link: http://pubs.acs.org/doi/10.1021/jacs.7b10922