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 (RhP) to platinum (Pt) as robust MOR electrocatalyst ascribing the excellent water dissociation capability of RhP to generate Pt(OH) species to mitigate the CO poisoning. MOR mass activity of RhP-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 RhP; moreover, the mutual electronic interplay between Pt and RhP contributes to a superior resistance towards electrochemical dissolution and coalescence. The theoretical investigation also indicates that d band center of Pt in RhP-Pt is downshifted resulting in a lower CO binding strength.