Synergistic effects of platinum–cerium carbonate hydroxides–reduced graphene oxide on enhanced durability for methanol electro-oxidation

Abstract

The durability of electrocatalysts for the methanol oxidation reaction (MOR) is currently the main concern for the commercial application of direct methanol fuel cells (DMFCs). In this work, a hybrid electrocatalytic material consisting of Pt nanoparticles, Ce(CO₃)OH nanoparticles and reduced graphene oxide (rGO) has been synthesized through a facile two-step solution method. Compared to Pt/C and Pt/rGO materials, the Pt–Ce(CO₃)OH/rGO electrocatalyst exhibits excellent activity and operational durability towards the MOR in alkaline solution. Impressively, an activity of higher than 52% (540 mA mg⁻¹) is retained for the hybrid electrocatalyst after 14 400 s chronoamperometric measurement, and the catalytic activity could be fully reactivated in clean KOH through a few CV cycles. The enhanced properties can be ascribed to the Ce–OH–Pt interface which could effectively promote the oxidation of carbonaceous poisons on Pt sites. Furthermore, Ce³⁺ in Ce(CO₃)OH can also greatly promote the transformation from oxidation state Pt^δ+ into metallic state Pt⁰, favoring the oxidation reaction of methanol on Pt. The synergistic effects provide us a new strategy of structure engineering for highly efficient methanol oxidation.