Cooperative Dinuclear Activation of a Formate Intermediate in the Hydrogenation of CO₂ to Methanol

CO₂ hydrogenation to methanol is achieved by homogeneous catalysts through a formic acid derivative. Previous studies have focused on using large amounts of additives to activate this intermediate, such as strong acids, amines and alcohols. Hydrogenation of CO₂ under basic conditions has been reported to only produce highly stable formate salts. We present in this contribution a novel method for formate activation that allows for CO₂ hydrogenation to methanol under basic conditions, by bimetallic activation of the formate salt by a cobalt and a nickel complex. From various catalytic and stoichiometric experiments, we propose that the nickel catalyst binds the in situ-generated formate to activate it for intramolecular cobalt hydride transfer, leading to an intermediate that can be further hydrogenated to methanol. This strategy could open new avenues in CO₂ hydrogenation under basic conditions, with implications for both homogeneously and heterogeneously catalyzed processes.