Electrochemical Ultrathin Metal-Atomic Layer Deposition for Silica Microenvironment-Assisted Cu-Based Catalysis

Replacing commonly used precious and rare noble metals by the abundant copper (Cu)-based catalysts is highly desired for sustainable fine-chemical synthesis. However, in the lack of model platforms, complex surface chemistry of randomly nanostructured bulk Cu is notoriously challenging to understand and control. By synthesizing ultrathin 2D-Cu layer sandwiched inside the bilayer silica template, an unusual but critical cooperative role of Lewis basic amino-silica microenvironment for [Cu]-catalyzed selective hydrogenation of unsaturated CC bonds in diverse alkynes, ene-ynes, and alpha,beta-unsaturated (alkene) Michael acceptors is discovered. Newly developed nanospace-confined electrochemical (eChem) atomic layer deposition (NC-EAD) technique afforded < 2 nm ultrathin Cu(0)-layer intimately covered inside silica envelope. This model platform aided the detailed mechanistic study deciphering the unexpected finding - originally non-reactive Cu-film, just by a simple silica coating step, turning into an efficient catalyst for scalable fine-chemical synthesis. The concept of reactive metal surface-microenvironment manipulation, presents a new paradigm for controlling complex molecular interactions in heterogeneous catalysts.