钴基催化剂上乙烷氧化脱氢的催化作用  

Investigation of Catalysis Mechanism for Oxidative Dehydrogenation of Ethane over Cobalt-based Catalysts

作　　者：陈铜[1] 李文钊[2] 张晋芬[1] 吴瑛[1] 操小栋[1] 万惠霖[1] 

机构地区：[1]厦门大学化学系固体表面物理化学国家重点实验室物理化学研究所 [2]中国科学院大连化学物理研究所,大连116023

出　　处：《化学学报》2004年第18期1760-1764,共5页Acta Chimica Sinica

基　　金：国家重点基础研究发展规划项目 (No .G1 9990 2 2 4 0 8);福建自然科学基金 (No.E0 2 1 0 0 0 2 )资助项目

摘　　要：比较了氧化钴、氧化镍分别对乙烯、乙烷氧化的催化性能 ,结果发现 :乙烯在氧化钴较氧化镍上更易进一步深度氧化生成CO2 .通过对新制担载型Co 基催化剂随反应温度反复升、降温的乙烷氧化脱氢 (ODHE)性能研究 ,展现了氧化钴活性相与SiO2 载体相互作用对催化性能的影响 .Weiss原位磁研究结果表明 :SiO2 担载的氧化钴催化剂较难还原 ,即使在反应气中氧被完全耗完时 ,钴仍停留在Co2 + 的价态上 .通过对数十个担载和未担载、不同载体、不同担载量的Co 基催化剂的ODHE性能考察表明 :在Co 基催化剂上ODHE反应机理一般遵从Hetero homogeneous机理 .The catalytic properties of unsupported cobalt and nickel oxide catalysts toward ethane and ethylene oxidation were compared, and the results indicated that more ethylene as intermediate product can be subsequently oxidized into degradation products, COx, over the former than over the latter. As increasing and/or decreasing reaction temperature, the catalytic behavior of CoO/SiO2 prepared recently indicated that the aging of catalyst is very sensitive to the pretreatment condition. In-situ Weiss magnetism measurement result over supported cobalt oxide showed that the cobalt still remains as Co2+ even if the oxygen in feed has been consumed. It indicated that the cobalt reduction is difficult due to the interaction between active phase and support. That the catalytic activity is related to the ease of the Co(3+)reversible arrowCo(2+) transition, and a hetero-homogeneous mechanism reflected in ODHE reaction over cobalt-based catalysts was suggested.

关 键 词：钴基催化剂 乙烷 氧化脱氢 催化作用 Hetero-homogeneous机理 乙烯 

分 类 号：O643.3[理学—物理化学]