International Journal of Hydrogen Energy, Vol.41, No.4, 2144-2153, 2016
Preferential CO oxidation in a hydrogen-rich stream over gold supported on Ni-Fe mixed metal oxides for fuel cell applications
This paper reports the catalytic performance of gold nanoparticles supported on high surface area mixed metal oxides derived from Ni and Fe hydrotalcite-like precursors. The gold catalysts were prepared by deposition-precipitation and characterised by XRD, TGA, BET, H-2-TPR, XPS, ICP and HR-TEM. From HR-TEM analysis, gold particles ranging from 4 to 10 nm were observed. XPS surface analysis revealed that gold existed in the metallic state, whereas surface oxides were NiO and Fe2O3. For the preferential CO oxidation reaction, the 1.5 wt.% Au catalyst gave almost complete conversion (approximate to 40% selectivity) at 60 degrees C using 2 vol.% O-2 with the GHSV fixed at 12 000 h(-1). The addition of CO2 to the feed stream resulted in a 10-15% decrease in conversion, whereas the addition of H2O improved CO conversion. The addition of H2O to the feed containing CO2 showed signs that H2O mitigated the negative effect of CO2. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.