Nickel phosphide (NixPy) was grown on ceria and Gd-doped ceria (CGO) respectively and the resulting supported catalysts were examined in the autothermal reforming reaction of a surrogate diesel fuel, comprising of n-dodecane, naphthalene and thiophene. The catalytic NixPy sites could also induce generation of Ce3+ ions in the ceria support under the reducing atmosphere of ATR at 400-500 degrees C according to TPR and XPS analysis. On the contrary, doping ceria by 10 mol% Gd noticeably weakened generation of Ce3+ ions. The Ce3+ ions present at the surface of catalyst support act to sustain water-gas shift reaction as well as to enhance the stabilization of catalytic reactivity. The commercial steam reforming catalyst was adopted as benchmark and displayed weaker resistance to coking and sulfur deactivation than the ceria-supported NixPy catalyst. (C) 2012 Elsevier Ltd. All rights reserved.