Catalytic activity for steam methane reforming and physical characterisation of La_1-xSr_xCr_1-yNi_yO_3-δ

A novel anode La1-xSrxCr1-yNiyO3-delta (x = 0.1, 0.2, 0.3, 0.4 and y = 0.05, 0.1) for solid oxide fuel cells (SOFCs) operated under methane has been tested regarding its catalytic activity for methane steam reforming and its structure characterised. Powders were synthesised by solid-state reaction and catalytic activity studies were performed using gas chromatography. The steam/methane ratio was between 0.5 and 1. The highest catalytic activity was obtained with 30 mol% of strontium and 5 mol% of nickel, synthesised at 1400 degreesC for 4 h in air, which were probably the least harsh conditions necessary to achieve clean perovskite surfaces. Samples were observed to exhibit p-type conduction with a maximum in conductivity being observed near 40 mol% of strontium or slightly above 40 mol%. Thermogravimetric analysis (TGA) measurements performed in 5% H-2 showed that oxygen loss increased with the strontium content. Increasing the nickel content did not enhance the catalytic activity of these compounds; for a content of 10 mol% of nickel, reduction to nickel metal happened, decreasing catalytic performances. (C) 2004 Published by Elsevier B.V.