利用行星式球磨机，以NH₄HCO₃、Na₂CO₃和（NH₄）₂CO₃为沉淀剂，采用机械化学法制备3种负载型Ni-Al₂O₃催化剂（分别记为Ni-NH₄HC、Ni-NaC和Ni-NH₄C）。利用XRD、H₂-TPR、N₂吸附-脱附、SEM和TPH等对催化剂进行表征，考察沉淀剂对Ni-Al₂O₃催化剂晶相结构、还原特征、孔道结构、表面形貌和浆态床CO甲烷化性能的影响。结果表明，以（NH₄）₂CO₃为沉淀剂所制备的Ni-NH₄C催化剂比表面积较大；活性组分晶粒尺寸较小。催化剂性能评价表明，CO甲烷化的"初始段"约需1 h，Ni-NH₄C和Ni-NH₄HC试样在"稳定段"的CO转化率均较高，约为77%；而Ni-NH₄C的CH₄选择性更高，在90%左右，这与催化剂活性金属的"尺寸效应"有较大关联。

Taking NH₄HCO₃,Na₂CO₃ and (NH₄)₂CO₃ respectively as precipitants,three kinds of supported Ni-Al₂O₃ catalysts (labeled as Ni-NH₄C,Ni-NaC and Ni-NH₄HC) are prepared through mechanical chemical method based on planetary ball-milling machine.Crystal structure,reduction performance,pore structure and surface morphology of the catalysts are characterized via XRD,H₂-TPR,N₂ adsorption-desorption,SEM and TPH methods,and the effects of precipitants are studied.Catalytic performance of the catalysts for CO methanation is evaluated in a slurry bed.Results show that Ni-NH₄C catalyst presents a large specific surface area of 300.8 m²·g^-1 and a small active component Ni grain size of 6.00 nm.Evaluation results propose that the "initial stage" of CO methanation needs about 1 h.CO conversions over Ni-NH₄C and Ni-NH₄HC in the "stability stage" both are as high as 77%,while CH₄ selectivity over Ni-NH₄C can reach as high as 90%,which may be contributed to the "size effect" of the active component in the used catalyst.

高峰(1996-),男,硕士研究生,研究方向为工业催化,18096822032@163.com