Niobium Carbide Based Catalyst Supports for PEMFC Cathodes

Recent research has shown that alternative compositions such as metal carbides and nitrides can potentially present the required properties of conductivity and (electro)chemical stability to replace the carbon blacks conventionally used as electrocatalyst supports in Proton Exchange Membrane Fuel Cells (PEMFC). We are currently investigating a range of synthesis routes leading to electronically conductive and chemically stable support materials based on NbC with controlled morphologies and porosity. For instance, a template-assisted method associated with specific thermal treatments¹ has led to a nanostructured carbide with a high specific surface area (70 m² g^-1) and an electronic conductivity comparable to that of carbon (10³ S^.m^-1), while a synthesis route involving electrospinning and reduction in methane provides niobium carbide nanofibres. Furthermore, hollow structures with controlled porosity can be obtained by varying the synthesis parameters. These various supports have been catalysed by deposition of platinum nanoparticles, synthesised by a microwave assisted polyol method. This contribution will describe the chemical and electrochemical characterisation of Pt on NbC-based supports, and compare the properties to those of other candidate support materials such as titania and tin oxide.

1. J. Bernard D'Arbigny, G. Taillades, M. Marrony, D. J. Jones, J. Roziere, Chemical Communications, 47, 7950-7952 (2011).