A Nickel‐Based Perovskite Catalyst with a Bimodal Size Distribution of Nickel Particles for Dry Reforming of Methane

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 °C), no coke was found on LSTN0.1 after 100 h 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 °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 (14.5 nm average size) but the small Ni particles (2.5 nm average size) remained unchanged. The perovskite‐type catalyst LSTN0.1 with a bimodal size distribution of Ni particles showed excellent resistance to carbon deposition, which is due to the strong metal–support interaction and basicity. The faster reaction rate and the higher coke resistance of the small Ni particles means that the amount of deposited carbon is less than that for large Ni particles only.