Oxidative coupling of methane on Ce/Na/CaO catalysts

被引:9
|
作者
Pacheco, JGA [1 ]
Eon, JG [1 ]
Schmal, M [1 ]
机构
[1] COPPE, NUCAT, Program Engn Quim, BR-21945980 Rio De Janeiro, Brazil
关键词
methane oxidative coupling; Ce/Na/CaO; methane isoconversion;
D O I
10.1023/A:1019064310606
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
Oxidative coupling of methane was investigated on Na/CaO and Ce/Na/CaO catalysts with different sodium and cerium contents. The reaction was carried out in a micro fixed-bed flow reactor operating at atmospheric pressure, at 700 and 750 degrees C and molar ratio feed of CH4 : O-2 : N-2 = 50 : 10 : 40. Catalysts were compared at isoconversion and were characterized by BET, XRD and XPS. The addition of cerium to Na/CaO catalyst increased the specific activity by a factor of eight. These catalytic and characterization results were related to the presence not only of Na+O- active sites, formed by the introduction of Na+ in the CaO lattice, but also to peroxide active sites. A mechanism is proposed to explain the role of cerium in increasing the rate of the regeneration step of the O-s(-) and Na2O2 sites.
引用
收藏
页码:197 / 202
页数:6
相关论文
共 50 条