Electrolytic production of hydrogen from aqueous acidic methanol solutions

摘要

The electrochemical production of hydrogen (H_2) from liquid methanol in acidic aqueous media was investigated in a proton exchange membrane (PEM) electrolyser, comprising a two-compartment glass cell with a membrane electrode assembly (MEA) composed of a Nafion? 117 membrane and gas diffusion electrodes (GDE). Methanol electrolysis was studied at concentrations ranging from 0 to 16 M, where 0 M corresponds to water electrolysis. The influence of catalysts (Pt and Pt-Ru), catalyst support (C or black), operating temperatures (23, 50 and 75 ℃) and operating modes (dry and wet cathode) were evaluated in the static mode. A theoretical thermodynamic analysis of the system was done as a function of temperature. The limiting current densities, kinetic parameters, including the Tafel slopes and current exchange density, and apparent activation energies were determined.