Abstract: A series of α-alumina supports modified with W compound are prepared,and the effect of α-alumina supports modified by W auxiliary on the performance of Ag catalyst for ethylene epoxidation is studied.By means of BET,XRD,SEM,XPS and other characterization methods,the effect of W auxiliary on the morphology and pore structure of α-alumina support is studied.The effect of the surface modification of supports by W auxiliary on the size,distribution,shape,appearance characteristics,and silver-oxygen binding energy of the silver particles on the catalyst surface is studied.Study result indicates that W auxiliary can expand the channels and pore volume of α-alumina supports,enhance the interaction between silver and support surface,make the distribution of silver particles more uniform,slow the size growth,and prolong the aggregation time of silver particles.The long-term stability of the catalyst is evaluated in a micro fixed bed reactor,showing that the activity and stability of the Ag catalyst is significantly improved by W auxiliary modified α-alumina support.The optimum adding amount of W auxiliary in α-alumina supports is found for excellent selectivity of the catalyst.
孙欣欣. 助剂W改性α-氧化铝载体对乙烯环氧化银催化剂性能的影响[J]. 现代化工, 2020, 40(7): 175-179.
SUN Xin-xin. Effect of W auxiliary modified α-alumina support on performance of silver catalyst for epoxidation of ethylene. Modern Chemical Industry, 2020, 40(7): 175-179.
[1] 赵红,姜志全,张镇,等.利用多孔阳极氧化铝研究载体孔洞尺寸对负载银粒子团聚的影响[J].催化学报,2006,(5):381-385. [2] Mao C F,Vannice M A.High surface area α-aluminas Ⅲ oxidation of ethylene,ethylene oxide,and acetaldehyde over silver dispersed on high surface area α-alumina[J].Applied Catalysis A:General,1995,122(1):61-67. [3] Seyedmonir S R,Plischke J K,Vannicem A,et al.Ethylene oxidation over small silver crystallites[J].Journal of Catalysis,1990,123(2):534-549. [4] 甘霖,王弘轼,朱炳辰,等.环氧乙烷合成银催化剂宏观动力学及失活分析[J].化工学报,2001,52(11):969-973. [5] 陶氏环球技术公司.α-氧化铝的成形多孔体及其制备方法:101534938[P].2009-09-16. [6] 李金兵,张志祥,林强,等.硫酸钡改性对Ag/α-Al2O3催化剂的乙烯环氧化催化性能的影响[J].工业催化,2011,19(12):55-58. [7] Shima M,Jrakada H.Catalyst andprocess for the pmduction of ethylene oxide:EP,1308442[P].2002-11-02. [8] 吕荣先.环氧乙烷生产用银催化剂的研究新进展[J].石化技术,1996,(2):123-126. [9] 朱孟钦,张式.不同制备工艺和载体上负载银催化剂的银粒表观形貌[J].电子显微学报,1997,16(2):157-164. [10] Atkins M,Couves J,Hague M,et al.On the role of Cs,Cl and subsurface O in promoting selectivity in Ag/alpha-Al2O3 catalysed oxidation of ethylene to ethylene epoxide[J].J Catal,2005,235(1):103-113. [11] Minahan D M,Hoflund G B,Epling W S,et al.Study of Cs-promoted,α-alumina-supported silver,ethylene epoxidation catalysts Ⅲ.Characterization of Cs-promoted and nonpromoted catalysts[J].J Catal,1997,168(2):393-399. [12] 林强,覃成鹏,沈洋,等.乙烯环氧化反应中银催化剂助剂的研究进展[J].工业催化,2013,21(2):1-7.