CuFe2O4 spinel synergize with Pd as a robust electrocatalyst for formate oxidation reaction

Abstract

As an energy conversion device, direct formate fuel cell (DFFC) has attracted much attention due totheir security, affordability as well as high energy conversion efficiency. However, the whole performance of the DFFC is unsatisfactory because of the repaid activity loss induced by Hads-poisoning of anode Pd catalysts during the formate oxidation reaction (FOR). Herein, we induced a CuFe2O4 complex into Pd to enhance the activity and release the Hads-poisoning to prolong the durability. The results reflect that the *OH generation capacity of CuFe2O4 played an important role in the Hads-stripping (Pd-Hads + CuFe2O4-OHads → Pd + CuFe2O4 + H2O). After optimized PCFO-3 (Pd/CuFe2O4) not only show a super FOR activity of 4427 mA mgPd−1 mass activity and 243 mA cm−2 specific activity, but also show a novel cycle durability of 10,000 times CV cycles and 12 h long-term i-t operation with a termination activity of 26.95 mA mgPd−1. More interestingly, this PCFO-3 shows a self-adapting process which induced an activity enhancement of 27.6% due to the synergistic effect of CuFe2O4 and Pd. We believe this work paves a new avenue for matching counterparts to enhance the FOR activity and durability of Pd electro-catalysts cooperatively.