Matrix Material Study for in situ Grown Pt Nanowire Electrocatalyst Layer in Proton Exchange Membrane Fuel Cells (PEMFCs)

Abstract The cathode electrocatalyst layers were prepared by in situ growing Pt nanowires (Pt‐NWs) in two kinds of matrixes with various Pt loadings for proton exchange membrane fuel cells (PEMFCs). Commercial carbon powder and 20 wt.% Pt/C electrocatalyst were used as the matrix material for the comparison. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), polarization curves tests, and electrochemical impedance spectroscopy (EIS) were carried out to examine the effects of the matrix materials on the Pt‐NW growing and the electrode performance. The optimum Pt‐NW loadings of 0.30 mg cm −2 in the carbon matrix (CM) and 0.20 mg cm −2 for the Pt/C matrix (PM) were obtained. The results indicated that the Pt‐NWs grown in the CM had a better crystalline, longer size length and better catalyst activity than those in the PM. The mechanism of the matrix affection is further discussed in this paper.