The Binary Metal Oxides Catalysts for Increasing Hydrophobicity of the Electrodes in Direct Methanol Fuel Cells

The massive use of sustainable materials in energy devices is increasingly important for addressing global energy demand and environmental challenges. Key components, including conductive biocarbon, electrocatalyst development, and hydrophobicity management, play critical roles in enabling low-cost membrane electrode assemblies (MEAs) for direct methanol fuel cells (DMFCs). Binary metal oxide electrocatalysts have attracted considerable attention due to their advantageous properties, such as a high density of low-coordinated metal active sites, amorphous or partially amorphous structures with elevated surface energy, and cost-effective material availability. Among sustainable conductive materials, carbon binchotan exhibits synergistic behavior when combined with binary metal oxides, functioning effectively as an electrocatalyst support. Partial substitution of conventional conductive carbon with binchotan leads to measurable improvements in the MEA performance. Compared with previous studies, the present work demonstrates enhanced control over key electrochemical parameters through material selection and electrode design. The electrochemical characteristics of the MEA are primarily governed by two interrelated factors: hydrophobicity and electrical conductivity. Although excessive hydrophobicity can pose challenges, the optimized incorporation of binary metal oxides and binchotan contributes to improved mechanical integrity by mitigating surface cracking and physical degradation of the MEA. Furthermore, systematic variation in metal oxide composition reveals a clear correlation between oxide composition and electrode hydrophobicity, which in turn influences methanol transport and overall fuel cell performance.