Rational Engineering of Nanostructured AgM (M = Au, Pt, Pd) Bimetallic Electrodes via Galvanic Replacement for Glycerol Electrolysis

Abstract

Glycerol electrolysis to coproduce green H2 and valuable chemicals at low potential constitutes a promising strategy to phase out fossil fuels in the energy and chemical sectors. In the search for high-performance catalysts, novel metals such as Pt, Pd, and Au with well-designed nanostructures and high density of active sites have shown great promise. Through alloying with other metals, their electronic structure can be further tuned, impacting the catalytic activity. Among different synthesis methods for nanostructured alloy catalysts, galvanic replacement is particularly attractive as it enables the production of bimetallic and hollow nanomaterials with increased active site density and intrinsic activity. Herein, a proof-of-concept study of fabricating carbon paper electrodes with directly grown nanostructured AgM (M = Au, Pt, Pd) bimetallic catalysts is presented, which are prepared by galvanic replacement for glycerol electrolysis. Among them the AgPt catalyst exhibits highest activity with lowest starting potential for glycerol electrooxidation, while AgAu showed high stability and poisoning tolerance. The engineered electrode is tested in a membrane-electrode-assembly glycerol electrolyser with a cell voltage below 1 V at 100 mA, demonstrating the promise of galvanic replacement method in engineering active and stable electrodes for glycerol electrolysis.