A Review of Graphene-Based Electrocatalysts for Methanol and Hydrogen Oxidation: Design Strategies, Performance, and Prospects

The growing global demand for clean and efficient energy technologies has intensified research into fuel cells, particularly direct methanol fuel cells (DMFCs) and hydrogen fuel cells, as promising alternatives to fossil fuels. Central to their performance are electrocatalysts that drive the methanol oxidation reaction (MOR) and hydrogen oxidation reaction (HOR). Among various materials explored, graphene and its derivatives have emerged as highly attractive candidates due to their exceptional surface area, electrical conductivity, mechanical strength, and tuneable chemical properties. Despite encouraging progress, the development of high-performance graphene-based electrocatalysts still faces critical challenges, including sluggish reaction kinetics, catalyst poisoning, and limited long-term stability. Conventional noble metal catalysts like Pt offer high activity but suffer from high cost and poor durability, while non-noble alternatives often fall short in performance. These limitations underline a significant research gap in designing cost-effective, stable, and efficient graphene-based materials for MOR and HOR applications. This review critically analyzes the latest strategies employed in the design and functionalization of graphene-based electrocatalysts, including metal/metal oxide decoration, heteroatom doping, and hybrid nanostructures. It further evaluates their electrochemical performance, highlights current limitations, and discusses future prospects for their application in energy conversion systems. Key future research directions identified include machine learning–guided catalyst design, advanced operando characterization techniques to elucidate degradation mechanisms, and scalable synthesis strategies that bridge laboratory performance with practical fuel cell deployment. The findings of this review contribute to a deeper understanding of the structure–performance relationships in graphene-based electrocatalysts and support the advancement of next-generation fuel cell technologies. By promoting clean energy innovation, this work aligns with United Nations Sustainable Development Goal 7 (Affordable and Clean Energy), offering valuable insights to accelerate the transition toward a low-carbon, sustainable energy future.