超高温焙烧的Ni/Al_2O_3对甲烷部分氧化反应的催化活性  

Partial Oxidation of Methane over Ni/Al_2O_3 Catalyst Calcined at Ultrahigh Temperatures

作　　者：陈永东[1] 陈耀强[1] 梅大江[1] 张丽娟[1] 董文萍[1] 曹红岩[1] 陈宏[1] 龚茂初[1] 

机构地区：[1]四川大学化学学院,四川成都610064

出　　处：《催化学报》2008年第5期477-481,共5页

基　　金：国家重点基础研究发展计划(G1999022400)

摘　　要：考察了超高温焙烧的Ni/Al2O3对甲烷部分氧化反应的催化性能,发现该催化剂经还原后对甲烷部分氧化反应表现出较高的催化活性.X射线衍射结果显示,Ni/Al2O3催化剂在超高温（1200～1400℃）下焙烧后生成了NiAl2O4,且无相转移,进一步经950℃还原后催化剂中绝大部分Ni以单质Ni0形式存在.透射电子显微镜测试结果表明,不同超高温焙烧的催化剂经950℃还原后Ni晶粒的大小无明显差异.这说明超高温焙烧的Ni/Al2O3对甲烷部分氧化反应的高活性可归结为NiAl2O4的可还原性以及还原后Ni^0相似的晶粒尺寸.同时还发现,焙烧温度越高,生成的NiAl2O4的还原温度越高.The Ni/Al2O3 catalyst calcined at ultrahigh temperatures （1200-1400℃ ） was used in partial oxidation of methane （POM）, and the Ni/Al2O3 catalyst retained high activity for POM after reduction. The X-ray diffraction result indicated that NiAl2O4 was formed when the catalyst was calcined at ultrahigh temperatures, and there was no phase transition in the temperature range. After the catalyst was reduced by H2 at 950℃ , most of Ni in the catalyst existed as Ni^0, and the crystal size of Ni^0 was similar, which was confirmed by transmission electron microscopy. The excellent performance of the Ni/Al2O3 catalyst calcined at ultrahigh temperatures for the POM reaction was attributed to both the reducibility of NiAl2O4 and the similar crystal size of Ni^0. The higher the calcination temperature, the higher the reduction temperature for NiAl2O4.

关 键 词：镍 氧化铝 负载型催化剂 超高温焙烧 甲烷 部分氧化 还原 

分 类 号：O643.36[理学—物理化学]