Boosting catalytic activity toward methanol oxidation reaction for platinum via heterostructure engineering

Direct methanol fuel cell (DMFC) is hampered by the sluggish methanol oxidation reaction. In this work, we have invited rhodium phosphides (Rh₂P) to platinum (Pt) as robust MOR electrocatalyst ascribing the excellent water dissociation capability of Rh₂P to generate Pt(OH)_ads species to mitigate the CO poisoning. MOR mass activity of Rh₂P-Pt/C is enhanced by 2- and 3.5-time with relative to commercial Pt/C and PtRu/C, respectively; additionally, the CO anti-poisoning ability is also boosted by 2.4 folds than Pt/C. The in-situ electrochemical impedance spectroscopy test reveals that the water dissociation is accelerated by Rh₂P; moreover, the mutual electronic interplay between Pt and Rh₂P contributes to a superior resistance towards electrochemical dissolution and coalescence. The theoretical investigation also indicates that d band center of Pt in Rh₂P-Pt is downshifted resulting in a lower CO binding strength.