Ultralow-Pt Loading Strategies for Electrocatalytic Methanol Oxidation: Challenges and Opportunities

Abstract Direct methanol fuel cells represent a pivotal technology for next-generation portable power sources, offering high energy density and logistical advantages over gaseous H 2 . However, their widespread commercialization remains heavily constrained by high cost and limited availability of Pt, the benchmark electrocatalyst for the methanol oxidation reaction. Although minimizing Pt loading is an economic imperative, it introduces a severe technical challenge: achieving high catalytic activity and long-term durability in ultralow-Pt loadings is notoriously difficult due to sluggish reaction kinetics and rapid electrode surface poisoning by CO intermediates. This review critically analyzes recent breakthroughs in ultralow-Pt loading strategies, comprehensively categorizing them into geometric nanostructuring, compositional alloying, and atomic-level engineering approaches, with particular emphasis on single-atom and sub-nanometer cluster catalysts. We provide an in-depth discussion of the fundamental mechanisms governing atom utilization efficiency and highlight the crucial role of strong metal–support interactions in stabilizing vulnerable active sites. Furthermore, we address the notable gap that persists between laboratory half-cell performance and practical implementations in membrane electrode assemblies. By integrating emerging insights from advanced operando characterization and computational modeling, this review offers a strategic roadmap to overcome the persistent stability–activity trade-off, ultimately guiding the design of cost-effective, high-performance catalysts essential for a sustainable energy future. Graphical Abstract