Ternary CoPtAu Nanoparticles as a General Catalyst for Highly Efficient Electro-oxidation of Liquid Fuels

摘要

Efficient electro-oxidation of formic acid, methanol, and ethanol is challenging owing to the multiple chemical reaction steps required to accomplish full oxidation to CO2. Herein, a ternary CoPtAu nanoparticle catalyst system is reported in which Co and Pt form an intermetallic L1(0)-structure and Au segregates on the surface to alloy with Pt. The L1(0)-structure stabilizes Co and significantly enhances the catalysis of the PtAu surface towards electro-oxidation of ethanol, methanol, and formic acid, with mass activities of 1.55 A/mg(Pt), 1.49 A/mg(Pt), and 11.97 A/mg(Pt), respectively in 0.1 m HClO4. The L1(0)-CoPtAu catalyst is also stable, with negligible degradation in mass activities and no obvious Co/Pt/Au composition changes after 10 000 potential cycles. The in situ surface-enhanced infrared absorption spectroscopy study indicates that the ternary catalyst activates the C-C bond more efficiently for ethanol oxidation.