Characterization of Ga/ZSM-5 for the catalytic aromatization of dilute ethylene streams

被引:53
作者
Qiu, P [1 ]
Lunsford, JH [1 ]
Rosynek, MP [1 ]
机构
[1] Texas A&M Univ, Dept Chem, College Stn, TX 77843 USA
关键词
ethylene; aromatics; Ga/ZSM-5;
D O I
10.1023/A:1019046714762
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Ga/ZSM-5 is an effective catalyst for the conversion of dilute (3%) ethylene-in-methane reactant streams into aromatic hydrocarbons at 500-550 degrees C. A Ga loading as low as 0.5 wt% is sufficient to obtain maximum yields of aromatic products. At 520 degrees C, an ethylene conversion of 93%, with an aromatics selectivity of 81%, was obtained over a 5 wt% Ga/ZSM-5 catalyst. The conversion of ethylene into aromatics over Ga/ZSM-5 catalysts involves a complex sequence of oligomerization, isomerization, cracking, and cyclization reactions that occur on Bronsted acid zeolites in the zeolite. The role of the gallium, which exists as both Ga3+ at zeolitic exchange sites and as Ga2O3 within the channels and on the external surface of the calcined catalyst, is to promote dehydrogenation of the acid-catalyzed oligomerization and cyclization products.
引用
收藏
页码:37 / 42
页数:6
相关论文
共 18 条
[1]  
BRAGIN OV, 1989, IZV AKAD NAUK SSSR S, V2, P254
[2]   Dealumination of HZSM-5 zeolites .1. Calcination and hydrothermal treatment [J].
Campbell, SM ;
Bibby, DM ;
Coddington, JM ;
Howe, RF ;
Meinhold, RH .
JOURNAL OF CATALYSIS, 1996, 161 (01) :338-349
[3]   Steady-state production of olefins in high yields during the oxidative coupling of methane: Utilization of a membrane contactor [J].
Cordi, EM ;
Pak, S ;
Rosynek, MP ;
Lunsford, JH .
APPLIED CATALYSIS A-GENERAL, 1997, 155 (01) :L1-L7
[4]  
DEROUANE EG, 1986, J MOL CATAL, V38, P387
[5]   TRANSFORMATION OF LPG INTO AROMATIC-HYDROCARBONS AND HYDROGEN OVER ZEOLITE CATALYSTS [J].
GIANNETTO, G ;
MONQUE, R ;
GALIASSO, R .
CATALYSIS REVIEWS-SCIENCE AND ENGINEERING, 1994, 36 (02) :271-304
[6]   AROMATIZATION OF SHORT CHAIN ALKANES ON ZEOLITE CATALYSTS [J].
GUISNET, M ;
GNEP, NS ;
ALARIO, F .
APPLIED CATALYSIS A-GENERAL, 1992, 89 (01) :1-30
[7]  
HALL RB, 1994, ACS DIV PETROL CHEM, V39, P214
[8]   FRAMEWORK HYDROXYL-GROUPS OF H-ZSM-5 ZEOLITES [J].
JACOBS, PA ;
VONBALLMOOS, R .
JOURNAL OF PHYSICAL CHEMISTRY, 1982, 86 (15) :3050-3052
[9]   METHANE TO ETHYLENE WITH 85-PERCENT YIELD IN A GAS RECYCLE ELECTROCATALYTIC REACTOR-SEPARATOR [J].
JIANG, Y ;
YENTEKAKIS, IV ;
VAYENAS, CG .
SCIENCE, 1994, 264 (5165) :1563-1566
[10]  
MASHOCKI A, 1996, APPL CATAL A-GEN, V146, P391