Improvement of Ni-based catalyst properties and activity for dry reforming of methane by application of all-in-one preparation method

摘要

Abstract The catalyst activity and resistance to coke deposition are of great importance for DRM reaction and the catalyst preparation method is one way to evaluate these parameters, besides improving the catalyst properties. Therefore, the effect of two catalyst preparation methods (incipient wetness impregnation (IWI) and all-in-one (AIO) methods) of ceria-alumina-supported Ni-based catalysts on dry reforming of methane reaction was investigated. The catalysts were characterized by several characterization techniques. All-in-one method provided greater dispersion and a higher reduced fraction for the catalyst than the IWI method, besides increasing the presence of weak basic sites, which decreases carbon deposition. The catalytic tests exhibited higher conversions for the AIO catalyst (47 for CH4 and 61 for CO2) that can be attributed to the greater metal dispersion of this catalyst to detriment of the IWI catalyst (39 for CH4 and 53 for CO2) and to the higher amount of weak basic sites provided by the AIO preparation method. Nevertheless, the IWI catalyst showed higher TOF compared to the AIO catalyst due to the weaker metal–support interaction of the former catalyst, although this is compensated by the higher number of active sites of the AIO sample. Finally, all-in-one method arises as a promising catalyst preparation technique for catalysts applied to DRM reaction since this methodology increases metal dispersion, catalyst activity, and resistance to coking.Graphical Abstract