PtRu mesoporous nanospheres as electrocatalysts with enhanced performance for oxidation of methanol

Abstract

Composition and morphology are crucial factors in the design of Pt-based catalysts with high performance, particularly in direct methanol fuel cells (DMFCs). Herein, PtRu mesoporous nanospheres (PtRu MNs) with tunable compositions were synthesized via a facile method and then deposited on a carbon support to act as electrocatalyst materials for the methanol oxidation reaction (MOR). Superior catalytic activity, better catalytic stability, and good tolerance to CO were achieved by the optimum PtRu (2 : 1) MNs/C catalyst compared with Pt MNs/C. The mass activity on PtRu (2 : 1) MNs/C reached 111.77 mA mg_Pt⁻¹, which was approximately 6.45-fold higher than that of Pt MNs/C (17.33 mA mg_Pt⁻¹). Meanwhile, PtRu (2 : 1) MNs/C retained much more current density (84.7%) than Pt MNs/C (17.7%) after 500 cycles. The improved catalytic performance is due to several factors, including the formation of a mesoporous nanostructure with abundant active sites and the favorable effects of the Ru species. This work provides guidance toward designing and fabricating effective Pt-based electrocatalysts for DMFC applications.