(Invited) Ligand Protected Au-Based Nanoclusters: A New Materials Domain for Efficient Electrochemical CO_2 conversion with Broken Scaling Relationship

摘要

The possibility of direct integration with renewable electric sources adds more potential to the electrochemical method as a promising route for CO_2 conversion. In our previous joint experimental-computational efforts, Au_(25)(SR)_(18)~- nanoclusters having 25 gold atoms and 18 protecting thiolate ligands was the first Au nanocluster identified and utilized as catalysts for CO_2 electro-reduction to CO. Here, we present first principles-based method coupled with Poisson Boltzmann implicit solvation model to screen other known synthesized atomically precise nanostructures within this class of materials. We proposed a list of promising CO_2 reduction catalyst which has not yet been explored in the field to the best of our knowledge. The existence of strong scaling relationship between the carbon containing intermediates in transition metal catalysts poses mechanistic limitation for optimization of CO_2 reduction efficiency. In the case of the nanoclusters, we demonstrate that the covalent nature of the active site specifically stabilize the COOH intermediate breaking the preexisting scaling relationship between COOH and CO binding energies on metals. Our results point to the broader application of covalent aided active site in complex electrochemical processes. We anticipate that our study may hasten the expansion of the domain of materials for CO_2 reduction electro-catalysts into a new realm of ligand protected gold-based nanoclusters.