Unusually High Concentration of Alkyl Ammonium Hydroxide in the Cation–Hydroxide–Water Coadsorbed Layer on Pt

Interactions between a catalyst and electrolyte have paramount importance for the performance of electrochemical devices. Here, we present the cation–hydroxide–water coadsorption on the Pt surface by a rotating disk electrode and neutron reflectometry. The rotating disk electrode experiments show that the current density of Pt rapidly dropped at hydrogen oxidation potentials due to tetramethylammonium hydroxide (TMAOH)–water coadsorption....