PtCo/Polypyrrole-Multiwalled Carbon Nanotube Complex Cathode Catalyst Containing Two Types of Oxygen Reduction Active Sites Used in Direct Methanol Fuel Cells



Low oxygen reduction reaction (ORR) activity and high cost of noble metal catalysts are two major challenges in direct methanol fuel cells (DMFCs). Pt-based catalysts are considered as an ideal alternative to deal with these two problems. While the second component metals play only the role of synergy effect with Pt, they themselves are inert towards activity towards ORR. It is necessary to design a new route to ultilize the second component metal by forming CoNx ORR active site on the base of PtM catalyst. In this paper, PtCo/polypyrrole-multiwalled carbon nanotubes (PtCo/PPy-MWCNTs) catalyst containing two types of ORR active site (Pt and CoNx) was synthesized by one pot synthesis route. The effect and dynamic mechanism of the named CoNx active site towards ORR was discussed by X-ray photoelectron sprectroscopy and linear sweep voltammetry. PtCo/PPy-MWCNTs cathode catalyst showed improved activity towards ORR and great potential in DMFCs.