Highly active 40 wt.% PtRu/C anode electrocatalysts for PEMFCs prepared by an improved impregnation method

Highly active 40 wt.% PtRu/C electrocatalysts that can be used as anode in polymer electrolyte membrane fuel cells (PEMFCs) were fabricated by improved impregnation method that introduced formaldehyde as a reducing agent and HCl as a segmentation agent with heat treatments at various temperatures. The morphology of the prepared catalysts was characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD), which revealed that the PtRu particles on carbon after heat treatment at 300 °C had a very narrow size distribution in the range of 1.5–3.4 nm, and that the average size varied between 2.3 and 2.4 nm. The electrochemical active surface area of the prepared PtRu/C catalysts was determined by CO-stripping voltammetry. In particular, the PtRu nanostructure electrodes heat treated at 300 °C showed an excellent catalytic activity because of the metals’ large surface area as well as a sufficient degree of alloy formation for CO tolerance. The unit cell performance of the PtRu/C catalyst with heat treatment at 300 °C exhibited a power density of 0.67 W cm−2 which was higher than that of a unit cell with a commercial PtRu/C catalyst (E-TEK) with the same metal loadings.