Highly Selective Methanol Synthesis Using Electrochemical CO2 Reduction with Defect-Engineered Cu58 Nanoclusters

Atomically precise copper nanoclusters (Cu NCs) exhibit significant potential as catalysts for the electrocatalytic reduction of CO2. However, the range of products achievable with these NCs has been somewhat constrained. This study introduces an innovative design strategy to enhance the catalytic activity of Cu NCs by engineering their active sites. We achieve this by creating defects on a cubic Cu58 NC through the partial dislocation of Cu atoms at its vertices, leading to the ligand vacancies that exposes multiple Cu sites. Additionally, the dislocation of Cu atoms finely tunes the inner cationic geometries through altered cuprophilic interactions, resulting in discernable changes in their edges and vertices. When tested, these unique arrangements of Cu(I) atoms within the cluster prove effective in determining product specificities during electrochemical CO2 reduction. Density functional theory calculations correlate the product selectivity toward CH3OH for [Cu58H20(SPr)36(PPh3)7]2+ (Pr = CH2CH2CH3) NC to the enhanced edge Cu reactivity in binding CO and CHO intermediates, compared to [Cu58H20(SPr)36(PPh3)8]2+ and [Cu58H20(SEt)36(PPh3)6]2+ (Et = CH2CH3) NCs. This work underscores the potential of tailored structural designs of atomically precise nanocatalysts in steering electrochemical CO2 reduction toward unconventional products.