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采用等体积浸渍法制备了高镍负载量的13%Ni/SiO2(13Ni/Si)催化剂和低镍负载量的7%Ni-2%Ce/SiO2(7Ni-2Ce/Si)催化剂。通过N2物理吸附、XRD、FT-IR、TEM、H2-TPR/TPD等技术对催化剂进行表征,在连续流动微反装置上考察了催化剂的CO甲烷化活性。结果表明,在7Ni-2Ce/Si催化剂中NiO、CeO2和SiO2之间产生的相互作用,改变了Ni-O-Si键的化学环境,促进了氧化镍物种的分散和还原,进而提高了催化剂的活性比表面积,同时在催化剂表面形成了新的中等强度的CO吸附中心。与高镍负载量的13Ni/Si催化剂相比,低镍负载量的7Ni-2Ce/Si表现出更高的CO吸附能力和甲烷化活性。常压下,在CO体积分数1%和空速7 000 h-1的反应条件下,低镍负载量的7Ni-2Ce/Si催化剂上CO完全甲烷化最低温度为230℃,比高镍负载量的13Ni/Si低了30℃。
A 13% Ni / SiO2 (13Ni / Si) catalyst with high nickel loading and a 7% Ni-2% Ce / SiO2 (7Ni-2Ce / Si) catalyst with low nickel loading were prepared by the same volume impregnation method. The catalysts were characterized by N2 adsorption, XRD, FT-IR, TEM and H2-TPR / TPD techniques. The CO methanation activity of the catalysts was investigated on a continuous flow microreactor. The results show that the interaction between NiO, CeO2 and SiO2 in 7Ni-2Ce / Si catalyst changes the chemical environment of Ni-O-Si bond, promotes the dispersion and reduction of nickel oxide species, Active specific surface area, while the catalyst surface formed a new medium-strength CO adsorption center. The low Ni loading of 7Ni-2Ce / Si showed higher CO adsorption and methanation activity than the high Ni loading of 13Ni / Si catalyst. At atmospheric pressure, the CO full methanation temperature of 7Ni-2Ce / Si catalyst with low Ni loading was 230 ℃ under the reaction conditions of CO concentration of 1% and space velocity of 7 000 h-1, The 13Ni / Si is lower by 30 ℃.