Galvanostatic Electroshock Synthesis of Low Loading Au−Pt Nanoalloys Onto Gas Diffusion Electrodes as Multifunctional Electrocatalysts for a Glycerol-Fed Electrolyzer

Abstract

Water electrolysis is increasingly considered a viable solution for meeting the world′s growing energy demands and mitigating environmental issues. An inventive strategy to mitigate the energy requirements involves substituting the energy-intensive oxygen evolution reaction (OER) with biomass-derived glycerol electrooxidation. Nonetheless, the synthesis of electrocatalysts for controlling the selectivity towards added-value chemicals at the anode and efficient H2 generation at the cathode remains a critical bottleneck. Herein, we implemented a galvanostatic electroshock synthesis approach to control the reduction kinetics of Au(III) and Pt(IV) to grow ultra-low amount of gold-platinum alloys on a gas diffusion electrode (12–26 μgmetal cm−2) for glycerol-fed hydroxide anion exchange membrane based electrolyzer. The symmetric GDE-Au100–xPtx||GDE-Au100–xPtx systems showed a notable improvement in electrolyzer performance (GDE-Au64Pt36=201 mA cm−2) as compared to monometallic versions (GDE-Au100Pt0=18 mA cm−2, GDE-Au0Pt100=81 mA cm−2). Chromatography (HPLC) analysis underscores the critical importance of bulk electrolysis methodology (galvanostatic vs potentiostatic) for the efficient conversion of glycerol into high-value-added products. Regarding the electrical energy required to produce 1 kg of H2 for such an electrolyzer fed at the anode with glycerol, our results confirm a drastic decrease by a factor of at least two compared with conventional water electrolysis.