沉淀剂对Ni-Al2O3催化剂结构及基于浆态床的CO甲烷化性能的影响  

Influence of precipitant on structure of Ni-Al2O3 catalyst and its catalytic performance in CO methanation based on slurry-bed reactor

作　　者：高峰 邹梦[1] 莫文龙[1,2] 马凤云 刘帅[3] 杨桂花 GAO Feng;ZOU Meng;MO Wen-long;MA Feng-yun;LIU Shuai;YANG Gui-hua(Key Laboratory of Coal Clean Conversion&Chemical Engineering Process of Xinjiang Uyghur Autonomous Region,College of Chemistry and Chemical Engineering,Xinjiang University,Urumqi 830046,China;State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024,China;Xinjiang Tianyun Chemical Co.,Ltd.,Luntai 841600,China)

机构地区：[1]煤炭清洁转化与化工过程新疆维吾尔自治区重点实验室,新疆大学化学化工学院,新疆乌鲁木齐830046 [2]大连理工大学精细化工国家重点实验室,辽宁大连116024 [3]新疆天运化工有限公司,新疆轮台841600

出　　处：《现代化工》2020年第9期154-158,162,共6页Modern Chemical Industry

基　　金：大连理工大学精细化工国家重点实验室开放课题基金资助项目(KF1904)。

摘　　要：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-Na C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-NH 4 C can reach as high as 90%,which may be contributed to the“size effect”of the active component in the used catalyst.

关 键 词：甲烷化 Ni-Al2O3催化剂 机械化学法 沉淀剂 

分 类 号：O643.32[理学—物理化学]