Hydrogen evolution reaction on copper: Promoting water dissociation by tuning the surface oxophilicity

In order to probe the hydroxyl (OHad) adsorption energy as one of the possible descriptors for hydrogen evolution reaction (HER) in alkaline media, we performed studies on polycrystalline copper (Cu(Poly)), a well-known poor catalyst for HER. By employing three different preparation methods for Cu(Poly), we were able to establish links between surface oxidation extent, oxophilicity, hydrophilicity and their catalytic activity for the HER. Ultimately, we propose that the formation of Cu(I)-OHad---OH2 activated complex is essential for lowering the energy barrier for water dissociation, which leads to higher activity for the HER in alkaline media.