Strong impact of indium promoter on Ni/Al2O3 and Ni/CeO2-Al2O3 catalysts used in dry reforming of methane

Abstract

Herein, the promotion effect of only 0.3 wt% indium on 3% Ni/Al2O3 and 3% Ni/CeO2-Al2O3 catalysts prepared by deposition-precipitation over a commercial alumina and on the CeO2-modified support was studied. Catalyst characterization by XRD, TPR, XPS, TEM, CO-DRIFTS was performed. The catalytic properties were investigated and coke formation was analyzed under temperature ramped CH4-decomposition and in Dry Reforming of Methane (DRM). The unique impact of indium was compared to the well-known effects of ceria additive. The carbon deposition on Ni/Al2O3 blocking the reactor could be only delayed due to ceria on Ni/CeO2-Al2O3, while NiIn/Al2O3 was able to maintain the activity in DRM. Indium modifier acting in parallel with ceria over NiIn/CeO2-Al2O3 determined the least coking, but the least catalytic activity. The results were discussed in terms of double role of In, acting as a ceria modifier, upgrading its oxidative properties and as a metal modifier, getting alloyed with Ni.