Potential of 3D Hierarchical Porous TiO₂-Graphene Aerogel (TiO₂-GA) as Electrocatalyst Support for Direct Methanol Fuel Cells

Fuel cells have already demonstrated their potential for green energy generation. However, the low reaction performance becomes an obstacle in terms of large-scale commercial manufacturing. Accordingly, this work focuses on a new unique fabrication of three-dimensional pore hierarchy TiO₂-graphene aerogel (TiO₂-GA) supporting PtRu catalyst for anodic catalyst direct methanol fuel cell, which is facile, ecologically benign, and economical. In this work, a hydrothermal technique was used, followed by a freeze-drying technique and a microwave-assisted ethylene reduction technique. The structural properties of the studied materials were confirmed by UV/visible spectroscopy, XRD, Raman spectrum, FESEM TEM, and XPS. Based on existing structural advantages, the performance of PtRu/TiO₂-GA has been investigated on DMFC anode catalysts. Furthermore, electrocatalytic stability performance with the same loading (~20%) was compared to commercial PtRu/C. Experimental outcomes show that the TiO₂-GA support offered a significantly high surface area value of 68.44 m²g^-1, mass activity/specific activity (608.17 mAmg^-1/0.45 mA/cm²_PtRu) that is higher than commercial PtRu/C (79.11 mAmg^-1/0.19 mA/cm²_PtRu). In passive DMFC mode, PtRu/TiO₂-GA showed a maximum power density of 3.1 mW cm^-2, which is 2.6 times higher than that of the PtRu/C commercial electrocatalyst. This suggests that PtRu/TiO₂-GA has a promising possibility for methanol oxidation and may be used as an anodic element in DMFC.