Structure engineering of PtCu₃/C catalyst from disordered to ordered intermetallic compound with heat-treatment for the methanol electrooxidation reaction

Platinum based alloys are hereinto the mostly used methanol oxidation catalysts. However, there are limited ways to improve the methanol oxidation reaction (MOR) performance of catalysts in terms of both activity and stability. Herein we developed a simple heat-treatment method to synthesize PtCu₃/C intermetallic compound catalyst with lattice compression. The as-prepared PtCu₃/C-1000 exhibited high specific activity of 3.23 mA·cm^–1 and mass activity of 1,200 mA·mg_Pt^–1, which is much higher than the PtCu₃/C-untreated and commercial Pt/C catalysts, respectively. The XAS and DFT results shows the high activity of the catalyst towards MOR comes from the tightening of the Pt-M bond, which leads to the decrease of Fermi energy level and the make it difficulty in adsorbing carbon intermediates, thus releasing more active sites to promote the improvement of MOR performance. Moreover, the PtCu₃/C-1000 shows better stability which is due to the surface-rich Pt prevents Cu from dissolution.