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 H(2) 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 μg(metal) cm(-2)) for glycerol-fed hydroxide anion exchange membrane based electrolyzer. The symmetric GDE-Au(100-x)Pt(x)||GDE-Au(100-x)Pt(x) systems showed a notable improvement in electrolyzer performance (GDE-Au(64)Pt(36)=201 mA cm(-2)) as compared to monometallic versions (GDE-Au(100)Pt(0)=18 mA cm(-2), GDE-Au(0)Pt(100)=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 H(2) 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.