Research Highlight | Chemical Sciences and Engineering
Molecular catalyst microenvironment facilitates selective and efficient electrocatalysis
In a study published in ACS Catalysis, scientists showed how tuning the microenvironment of cobalt catalysts enables selective and efficient CO2 reduction, revealing new strategies for designing advanced electrocatalysts for fuel production.
Proposed CO₂-bound intermediate of molecular cobalt catalyst responsible for electrocatalytic CO₂ reduction
Scientific Achievement
Electrocatalytic CO2 reduction conditions that selectively yield CO were achieved using molecular Co(II) catalysts with redox-active ligands directly coordinating the metal center, and variable groups in the secondary coordination sphere (SCS). Under catalytic conditions, pendant pyridine groups are protonated and induce hydrogen-bonding networks that stabilize substrate-bound intermediates and accelerate catalysis.
Significance and Impact
This study expands the toolbox for enhancing intrinsic CO2R catalytic activity through SCS effects. The mechanistic insight revealed using high-resolution experimental and computational methods highlights the importance of tuning the structure of redox active ligands to avoid catalyst inhibition by the major product, CO.
Research Details
- Synthesized a library of molecular electrocatalysts that show strong correlations between SCS functionality and catalyst kinetics
- Mechanistic insight was uncovered using pulsed EPR, synchrotron XAS, electrochemical methods, IR analysis, and DFT calculations; confirms protonation of pendant pyridines and that strong CO binding leads to catalyst inhibition and precatalytic CO2R activity