Room-Temperature Formate Ester Transfer Hydrogenation Enables an Electrochemical/Thermal Organometallic Cascade for Methanol Synthesis from CO.

The reduction of CO to synthetic fuels is a valuable strategy for energy storage. However, the formation of energy-dense liquid fuels such as methanol remains rare, particularly under low-temperature and low-pressure conditions that can be coupled to renewable electricity sources via electrochemistry. Here, a multicatalyst system pairing an electrocatalyst with a thermal organometallic catalyst is introduced, which enables the reduction of CO to methanol at ambient temperature and pressure.

Kinetics of the Effect in Ruthenium Complexes Provide Insight into the Factors That Control Activity and Stability in CO Electroreduction.

Comparative kinetic studies of a series of new ruthenium complexes provide a platform for understanding how strong effect ligands and redox-active ligands work together to enable rapid electrochemical CO reduction at moderate overpotential. After synthesizing isomeric pairs of ruthenium complexes featuring 2'-picolinyl-methyl-benzimidazol-2-ylidene (Mebim-pic) as a strong effect ligand and 2,2':6',2″-terpyridine (tpy) as a redox-active ligand, chemical and electrochemical kinetic studies examined how complex geometry and charge affect the individual steps and overall catalysis of CO reduction. The relative effect of picoline vs the N-heterocyclic carbene (NHC) was quantified through a kinetic analysis of reductively triggered chloride dissociation, revealing that chloride loss is 1000 times faster in the isomer with the NHC to chloride.