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

摘要

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 14400 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 delta+ into metallic state Pt-0, favoring the oxidation reaction of methanol on Pt. The synergistic effects provide us a new strategy of structure engineering for highly efficient methanol oxidation.