Nanostructured PtRu/C catalyst promoted by CoP as an efficient and robust anode catalyst in direct methanol fuel cells

Artikel i vetenskaplig tidskrift, 2015

Nanostructured PtRu material is considered as the best catalyst for direct methanol fuel cells (DMFCs), but the performance decay resulting from Ru loss seriously hinders the commercial application. Here we demonstrated that the performance of nanostructured PtRu catalyst for methanol oxidation could be significantly improved by CoP material; the presence of CoP could largely slow down the loss of Ru and Pt in PtRu catalyst system, thus promising a highly active and durable performance in DMFCs. Cyclic Voltammetry results showed the peak current is 2.89 times higher than that of state-of-the-art commercial PtRu/C-JM (231.9mAmg-1 PtRu ) and 3.86 times higher than that of the home-made reference (PtRu/C-H) catalyst (173.6mAmg-1 PtRu ); kinetics study probed by electrochemical impedance spectroscopy showed a large reduced charge transfer resistance in the rate determining step. The highest maximum power density was achieved on this novel PtRu-CoP/C catalyst among all the evaluated catalysts at different temperatures. Specifically, a maximum power density of 85.7mWcm-2 achieved at 30°C is much higher than that of state-of-the-art commercial PtRu/C catalyst at 70°C (63.1mWcm-2). Outstanding catalytic activity and stability observed on this novel PtRu-CoP/C catalyst should be attributed to a synergistic effect between the nanostructured PtRu and CoP, in which the presence of CoP increases PtRu physical stability and anti-CO poisoning ability. The present work is a significant step that opens an avenue in the development of highly active and durable catalysts for fuel cells technology, and makes PtRu catalyst system much closer for commercial application in DMFCs.