Enhancing Direct Ethanol Fuel Cell Performance: Mesoporous Carbon Functionalization for Optimized PtRe Catalysts

The development of advanced anode electrocatalysts for direct ethanol fuel cells (DEFCs) faces key challenges related to the complete oxidation of ethanol, particularly the cleavage of the CC bond. This study investigates the impact of chemical functionalization (using HNO₃, H₂O₂, and urea) of mesoporous carbon (MC) supports on the performance of Pt and PtRe catalysts. Functionalization modifies the carbon structure, introducing nanowindows or causing wall degradation, altering conductivity and surface chemistry without significantly affecting particle size. Catalysts synthesized by the polyol method are characterized structurally, texturally, and electrochemically. The results demonstrate that Re addition enhances ethanol electrooxidation through synergistic effects with Pt, reducing onset potentials and increasing electrochemically active surface areas, particularly at an optimal Re loading of 3 wt%. Functionalized supports, especially MC-HNO₃, further improve catalyst dispersion and electrochemical performance. Prototype fuel cell tests confirm these trends, highlighting the importance of metal synergy and carbon surface functionalization.