Ordered Porous Electrodes by Design: Toward Enhancing the Effective Utilization of Platinum in Electrocatalysis

Abstract

Platinum‐nanoparticle‐functionalized, ordered, porous support electrodes are prepared and characterized as a potential new class of oxygen reduction reaction (ORR) electrocatalysts. This study aims to develop electrode materials that enhance the effective utilization of Pt in electrocatalytic reactions through improved mass transport properties, high Pt mass specific surface area, and increased Pt electrochemical stability. The electrodes are prepared using modular sacrificial templates, producing a uniform distribution of Pt nanoparticles inside ordered porous Au electrodes. This method can be further fine‐tuned to optimize the architecture for a range of characteristics, such as varying nanoparticle properties, pore size, or support material. The Pt‐coated Au, ordered, porous electrodes exhibit several improved characteristics, such as enhanced Pt effective utilization for ORR electrocatalysis. This includes a nearly twofold increase in Pt mass specific surface area over other ultrathin designs, superior mass transport properties in comparison to traditional catalyst layers of C black supported Pt nanoparticles mixed with ionomer, good methanol tolerance and exceptional stability toward Pt chemical and/or electrochemical dissolution through interfacial interactions with Au. The methods to prepare Pt‐coated ordered porous electrodes can be extended to other architectures for enhanced catalyst utilization and improved performance of Pt in electrochemical processes.