Zn对Ni/SiO_(2)催化剂苯甲醚氢脱氧性能的影响  

Effect of Zn on performance of Ni/SiO_(2)for hydrodeoxygenation of anisole

作　　者：王丹丹 谷孝雨 史浩楠 陈吉祥[1] WANG Dan-dan;GU Xiao-yu;SHI Hao-nan;CHEN Ji-xiang(Tianjin Key Laboratory of Applied Catalysis Science and Technology,Department of Catalysis Science and Engineering,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学化工学院催化科学与工程系天津市应用催化科学与工程重点实验室,天津300350

出　　处：《燃料化学学报》2022年第10期1341-1350,共10页Journal of Fuel Chemistry and Technology

基　　金：supported by the National Natural Science Foundation of China(21576193 and 21176177)。

摘　　要：采用等体积浸渍法制备了Ni/SiO_(2)及NixZn/SiO_(2)(x代表Ni/Zn原子比)催化剂,在常压固定床反应器上考察了催化剂苯甲醚气相加氢脱氧性能。研究发现,经550℃还原后NixZn/SiO_(2)中形成了Ni-Zn合金,当Ni/Zn原子比为30时可获得较小合金晶粒尺寸和较高H2化学吸附量。在苯甲醚加氢脱氧反应中,Ni-Zn合金的形成有利于苯甲醚直接脱氧形成苯,同时抑制了CO甲烷化及C-C键氢解,这是因为形成合金后亲氧性金属Zn对Ni的几何隔离作用。Ni_(30)Zn/SiO_(2)催化剂的活性和苯选择性均高于Ni/SiO_(2)。结果表明,Ni_(30)Zn/SiO_(2)催化剂失活与产物水氧化Ni-Zn合金表面及积炭有关。Herein,SiO_(2) supported metallic Ni(Ni/SiO_(2)) and bimetallic Ni-Zn(NixZn/SiO_(2))(x represents the Ni/Zn atomic ratio)catalysts were prepared by the incipient wetness impregnation method and their activities were tested in vapor phase hydrodeoxygenation(HDO)of anisole under 0.1 MPa.The characterization results show that Ni-Zn alloy forms in NixZn/SiO_(2) after reduction at 550℃,and a suitable Ni/Zn atomic ratio(30)leads to smaller alloy particle size and consequently more H2 adsorption amount than others.In the HDO reaction,the formation of Ni-Zn alloy facilitates the direct deoxygenation pathway and suppresses CO methanation and C-C bond hydrogenolysis,which is ascribed to the isolation effect of the Ni atoms by the oxophilic Zn ones.Ni_(30)Zn/SiO_(2) gives not only higher anisole conversion but also higher selectivity to benzene than Ni/SiO_(2).Therefore,the introduction of a suitable amount of oxophilic Zn in Ni/SiO_(2) promotes the HDO of anisole to benzene.Finally,we propose that the Ni_(30)Zn/SiO_(2) deactivation is related to the oxidation of Ni-Zn alloy and carbon deposition on the catalyst surface.

关 键 词：Ni-Zn合金 加氢脱氧 直接脱氧 甲烷化 C-C键氢解 

分 类 号：O643[理学—物理化学]