Nanostructured palladium catalyst poisoning depressed by cobalt phosphide in the electro-oxidation of formic acid for fuel cells

Abstract

Abstract Nanostructured palladium is considered as the best catalyst materials for direct formic acid fuel cells but catalyst poisoning suffering from the intermediates seriously reduces catalytic activity and stability, thus further hinders the commercial application of fuel cells technology. Herein, we report the tricky Pd catalyst poisoning problem could be greatly depressed by cobalt phosphide (CoP) material during formic acid oxidation, so an extremely active and stable Pd catalyst with very low Pd loading (5 wt%) is realized. The high anti-poisoning ability was evidenced by a significantly faster kinetics study and less poisoning intermediates adsorbed on its surface compared with Pd/C catalyst. When integrated into a real fuel cells model, a power density of 150 mW cm −2 catalyzed by this Pd-CoP/C catalyst (5 wt%, Pd) was comparable to that of the commercial Pd/C catalyst (20 wt%, Pd) indicating a very promising application in the electrochemical energy devices. This work opens an avenue to overcome the universal catalyst poisoning issue and pushes Pd catalyst system much stronger for commercial application in fuel cells technology.