Longevity increase of an impregnated Ni/CeO2-Al2O3 dry reforming catalyst by indium

The catalytic and structural changes due to the presence of 0.25 wt% indium on a 3% Ni/CeO2-Al2O3 catalyst prepared by impregnation method were investigated. Catalyst characterizations by XRD, TPR, XPS, TEM and DRIFTS (in presence of CO/CO2/CH4 +CO2) were carried out. In the short (6 h) catalytic methane dry reforming tests at 650 °C both samples were stable, produced essentially no carbon, but indium lowered the activity. In the 4 day longevity tests at 675 °C, stable activity was achieved by the In-promoted catalyst in contrast with the continuous deactivation of the unpromoted Ni sample due to coking and sintering. Indium, partially alloyed with nickel, could better keep nickel in metallic state, and the increased CO2 activation ability, the intimate Ni(In)-CeO2 interface inside the support pores resulted in practically no coking.