Regulating the Alloying Degree and Electronic Structure of Pt–Au Nanoparticles for High-Efficiency Direct C2+ Alcohol Fuel Cells

Direct alcohol fuel cells represent a promising green and sustainable route for chemical to electrical energy conversion; however, designing highly efficient electrocatalysts for the electro-oxidation of C 2+ alcohol molecules is an ongoing challenge. Herein, we report a convenient room-temperature reduction method to fabricate a series of Pt–Au alloy catalysts with controllably tailored alloying degrees and particle diameters (4.6–7.9 nm) for enhancing the electro-oxidation capability toward C 2+ alcohols. Benefiting from the strong electron interactions between Pt and Au, the electronic state and size of the alloy nanoparticles can be effectively optimized, alleviating the CO poisoning and aggregation problem of the catalytic species. As a result, the Pt 45 Au 55 alloy nanoparticles grown in situ on carbon nanotubes (Pt 45 Au 55 /CNTs) show an enhanced C–C bond cleavage ability, as confirmed by a quantitative analysis of the final C 2 oxidation products as well as by comparing the oxidation activity in different C 1 –C 3 alcohols and other high-energy-density molecules. The Pt 45 Au 55 /CNTs catalyst exhibits excellent catalytic activity (1746 mA·mg Pt –1 ), high CO tolerance, and good stability for the ethanol oxidation reaction (EOR) in an acidic medium. Moreover, the Pt 38 Au 62 /CNTs catalyst displays dramatically enhanced ethanol oxidation activity (13 993 mA·mg Pt+Au –1 ) in an alkaline medium. The proposed rational design of Pt–Au alloy catalysts with controllable alloying degrees and particle sizes provides a feasible strategy for boosting the overall performance of Pt-based electrocatalysts for the direct C 2+ alcohol fuel cells.