Graphitic carbon nitrides are investigated for developing highly durable Pt electrocatalyst supports for polymer electrolyte fuel cells (PEFCs). Three different graphitic carbon nitride materials were synthesized with the aim to address the effect of crystallinity, porosity, and composition on the catalyst support properties: polymeric carbon nitride (gCNM), poly(triazine) imide carbon nitride (PTI/Li+Cl–), and boron-doped graphitic carbon nitride (B-gCNM). Following accelerated corrosion testing, all graphitic carbon nitride materials are found to be more electrochemically stable compared to conventional carbon black (Vulcan XC-72R) with B-gCNM support showing the best stability. For the supported catalysts, Pt/PTI-Li+Cl– catalyst exhibits better durability with only 19% electrochemical surface area (ECSA) loss versus 36% for Pt/Vulcan after 2000 scans. Superior methanol oxidation activity is observed for all graphitic carbon nitride supported Pt catalysts on the basis of the catalyst ECSA.

A novel PdIr/C supported alloy nanoparticle catalyst has been developed for use in the hydrogen oxidation reaction (HOR) at the anode of an Alkaline Anion Exchange Membrane (AAEM) fuel cell. The catalyst has been characterized using Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX) and Synchrotron X-ray Powder Diffraction (SXPD). Electrochemical testing suggests it has a comparable activity for HOR as Pt/C and is a good candidate for use on the anode of an AAEM fuel cell.

Text: Many electrochemical studies exist using the acidic ionomer Nafion ® as a binder in the ink formulation when operating in high pH systems. However, Nafion ® acts as an ionic insulator for OH-, and for reactions such as the hydrogen oxidation reaction, the transport of OHto the catalyst surface is of utmost importance when elucidating the performance of a catalyst. This work demonstrates that when using an alkaline polymer binder in the ink, the apparent activity of a commercially synthesised Pt/C catalyst is increased due to a lower diffusion resistance for the reaction. In order to obtain accurate values for kinetic data in alkaline media, the use of the acidic binder should be avoided.

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