Lanthanum-Promoted nickel-based catalysts for the dry reforming of methane at low temperatures

Abstract

In recent decades, considerable attention has been paid to the catalytic dry reforming of methane to obtain syngas. This reaction has very important environmental implications due to the utilization of CH4 and CO2, gases that contribute to the greenhouse effect. The dry reforming of methane is normally carried out over strong basic catalysts with noble metals. Nickel has emerged as an interesting alternative, although it tends to deactivate and form carbon whiskers, which could block the reactor. It is therefore necessary to improve their catalytic performance (conversion, selectivity and stability). In this work, Ni0.69La0.31 and Ni0.14Mg0.55La0.31 were studied in the dry methane reforming reaction. The precursors were prepared by co-precipitation and the oxide phases were obtained by calcining these precursors at 450°C/6 h. The XRD diagrams of the calcined samples show the formation of mixed oxide phases with a periclase-like structure. Analysis of the temperature-programmed reduction shows that the presence of Mg shifts the reduction to higher temperatures. The catalysts, reduced at 650°C, were tested in this reaction as a function of operating time at 650°C. No deactivation occurred after 20 h of operation. Furthermore, the combination of Mg and La drastically improves the conversion and selectivity of the catalyst (> 95%)