Electrochemical Evaluation of Tungsten Monocarbide (WC) and Platinum-modified WC as Alternative DMFC Electrocatalysts

Tungsten monocarbide (WC) nanoparticles, with and without platinum (PI) modification, have successfully been integrated as a functioning anode electrocatalyst in direct methanol fuel cell (DMFC) devices. The membrane electrode assembly (MEA) for these DMFC devices was fabricated using a conventional hot-pressing technique and tested in comparison to a similarly prepared MEA using standard Pt-Ru as the anode electrocatalyst. Evidence for methanol activity of fuel cell anodes containing only WC was observed at open-circuit conditions. Upon the withdrawal of current from these devices, a steadily decaying performance could be reproducibly observed In the case of Pt-modified WC nanoparticles, the electrocatalyst demonstrated clear evidence of stability and activity. It was observed that the power output per mg of Pt in the Pt/WC anode is approximately equal to the output per mg of Pt plus Ru in the Pt-Ru anode. The demonstration of activity, stability, and ease of integration into the fuel cell device provides a strong motivation to further investigate and optimize the synthesis of Pt-modified WC nanomaterials for commercial use in fuel cell applications.