Rational design of nickel-based catalyst coupling with combined methane reforming to steadily produce syngas

Abstract

Inhibiting the aggregation of Ni particles and coke deposition on supported nickel catalysts has always been an enormous challenge in methane reforming to syngas. To address the problem, in this study, a Ce-Al-O supported Ni mesoporous catalyst (Ni/Ce-Al-O-A) was designed and synthesized by using evaporation-induced self-assembly (EISA) method and citric acid auto-reduction (AR) method, respectively. The prepared Ni/Ce-Al-O-A catalyst, without further reduction, was used for combined methane dry reforming comprising CO2 dry reforming of methane (DRM) and methane partial oxidation (MPO) to effectively produce syngas. Employing citric acid auto-reduction method for catalyst preparation directly led to the formation of metallic Ni by calcining the precursor of Ni/Ce-Al-O-A in argon atmosphere, with high dispersion and small particle size (at around 4.5 nm) of metallic Ni being obtained. The Ni/Ce-Al-O-A catalyst presented high catalytic activity, better than those of reference catalyst prepared by general impregnation method and the commercial alumina supported Ni catalyst synthesized by citric acid auto-reduction method. In a 250 h lifetime test, the Ni/Ce-Al-O-A catalyst exhibited an extremely catalytic stability and anti-coking ability, and no deactivation was observed. The excellent catalytic activity of Ni/Ce-Al-O-A catalyst was mainly attributed to the Ce-incorporated Ce-Al-O that facilitated the adsorption and activation of CO2 as well as the combined methane reforming (DRM-MPO) in which the existing oxygen could effectively inhibit the coke formation.