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采用共浸渍法制备了NiO-MoO_3/Al_2O_3催化剂,利用N_2物理吸附、XRD、H_2-TPR、H_2-TPD和TG等手段对催化剂的结构和性质进行表征,并考察了其在低H_2/CO摩尔比(约为1)和微量硫(5μg/g)的条件下进行CO甲烷化的催化性能。结果表明,MoO_3的引入能减弱Ni物种与载体间的强相互作用,提高催化剂的还原性能,增加Ni活性中心数。随着MoO_3质量分数的增加,催化剂的甲烷化性能先升高后降低,在MoO_3质量分数为3%时甲烷化性能最佳。积碳和硫中毒是催化剂失活的主要原因,适量MoO_3的添加能提高催化剂对H_2的吸附能力,增强催化剂的抗积碳性能,同时还能缓解硫中毒引起的失活,从而明显改善催化剂的稳定性。
NiO-MoO 3 / Al 2 O 3 catalysts were prepared by co-impregnation method. The structures and properties of the catalysts were characterized by means of N 2 adsorption, XRD, H 2 -TPR, H 2 -TPD and TG methods. (About 1) and trace sulfur (5 μg / g) under the conditions of CO methanation catalytic performance. The results show that the introduction of MoO 3 can weaken the strong interaction between the Ni species and the support, improve the reduction performance of the catalyst and increase the number of Ni active centers. With the increase of mass fraction of MoO_3, the methanation performance of the catalyst first increased and then decreased, and the methanation performance was best when the mass fraction of MoO_3 was 3%. Coke and sulfur poisoning are the main reasons for catalyst deactivation. Appropriate amount of MoO 3 can improve the adsorption capacity of H 2 on the catalyst, enhance the anti-carbon deposition property of the catalyst and at the same time relieve the deactivation caused by sulfur poisoning, stability.