Grain boundary engineered bifunctional PtCuMo aerogel for anodizing reactions in broad-spectrum direct liquid fuel cells

The operational efficiency of membrane electrode assemblies in direct liquid fuel cells is critically dependent on the fuel purity in the anode compartment. To address the inherent challenge of fuel mixing problem in alcohol systems, we propose a rational catalyst design strategy focusing on morphological and compositional optimization. Sodium borohydride-derived PtCuMo alloy aerogels (AA) exhibit abundant grain boundary defects, while solvothermally prepared nanowire arrays (NA) maintain excellent single-crystalline characteristics. Density functional theory calculations demonstrate that engineered grain boundaries can effectively broaden the adsorption energy window for key reaction intermediates, enabling superior adaptability to diverse catalytic pathways. By precisely controlling Cu content, we identified Pt₃Cu₃Mo_0.5 AA as the optimal catalyst configuration, demonstrating 150% enhancement in methanol oxidation reaction activity compared to Pt₃Cu₆Mo_0.5 NA (1.5 vs. 0.6 A·mg_Pt⁻¹) and 17% improvement in ethanol oxidation reaction performance versus Pt₃Cu₁Mo_0.5 NA (0.82 vs. 0.70 A·mg_Pt⁻¹). Practical application testing using gas diffusion electrodes (anode loading: 0.85 mg_Pt·cm⁻²) achieved a mass-specific power density of 14.14 W·g_Pt⁻¹ in 1:1 methanol/ethanol blends, representing a 3.5-fold improvement over commercial Pt/C benchmarks. This work establishes a fundamental framework for developing high-performance, broad-spectrum electrocatalysts in advanced fuel cell systems.