Gold micromeshes as highly active electrocatalysts for methanol oxidation reaction

Abstract

A high density of surface defects is a key factor for efficient nanoscale gold (Au) electrocatalysts for the oxidation of small organic molecules. Here we present tunable pore size Au micromeshes with a high density of steps, kinks, twin boundaries, and stacking faults fabricated by using a template method. Electrocatalytic measurements on the methanol oxidation reaction show that the peak current density (normalized to the electrochemical surface area) of our Au mesh in alkaline electrolyte (0.5 M KOH) can reach 0.264 mA cm⁻², which is significantly higher than those of the well-studied nanoporous Au film (0.081 mA cm⁻²) and nanoporous Au nanoparticles (0.112 mA cm⁻²). Over 90% of the current density can be maintained after 500 cycling tests. Through transmission electron microscopy studies, the superior intrinsic activity and stability lie in the high linear density of surface defects, the exposure of active facets, and superficial tensile strain on the outter-most layers.