ChemCatChem

2018, 10,

The critical problem facing Ni-based catalysts for the CO2 reforming of methane (DRM) is the serious carbon deposition and metal sintering, which are sensitive to the size of Ni particles. A perovskite-type catalyst La0.46Sr0.34Ti0.9Ni0.1O3 (denoted as LSTN0.1) with a bimodal size distribution of Ni particles was prepared by combustion method. Under mild DRM conditions (CH4:CO2=1:1.2 at 700 degrees C), no coke was found on LSTN0.1 after 100h reaction, and the comparison with the impregnated catalysts showed that the carbon resistance is closely associated with the strong metal-support interaction and basicity. Nevertheless, under harsh reaction conditions (CH4:CO2=2:1 at 700 degrees C), the coking process speeded up on LSTN0.1. This bimodal Ni catalyst had higher coke resistance than the catalyst possessing few small particles. Moreover, the coke was found on the large Ni particles (14.5nm average size) but the small Ni particles (2.5nm average size) remained unchanged.