氮化钼催化剂上丁二烯吸附物种的程序升温表面反应  

Temperature-Programmed Surface Reaction of Butadiene on Molybdenum Nitride Catalyst

作　　者：郝志显[1] 吴自力[1] 魏昭彬[1] 李灿[1] 辛勤[1] 闵恩泽[2] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,大连116023 [2]中国石油化工集团公司石油科学研究院,北京100083

出　　处：《催化学报》2000年第4期367-371,共5页

基　　金：国家自然科学基金!资助项目 ( 2 962 53 0 5)

摘　　要：使用程序升温表面反应的方法对氮化钼催化剂上的丁二烯吸附物种进行了考察 .结果表明 ,当用氢气对吸附丁二烯后的氮化钼进行吹扫时 ,表面大量脱附的是可逆吸附的σ π配位的C4物种 ;1 2 0℃脱附的产物可能是丁川物种 ;32 0℃ (钝化态为 360℃ )出现了丁二烯的加氢和裂解产物 ,为强吸附的碳氢物种 ;聚合物的脱附出现在1 2 0～ 360℃ ,其脱附温度随反应条件或催化剂的不同而变化 .新鲜态和钝化态催化剂在不同温度区域的脱附物种有所不同 ,根据催化剂表面上活性位的差异对此进行了讨论 .The surface species from butadiene adsorption on γ Mo 2N have been investigated by temperature programmed surface reaction (TPSR). The C 4 hydrocarbons desorbed at 60 ℃ can be attributed to the σ π complex formed between butadiene and Mo sites. They are reversibly adsorbed on the catalysts and can be easily removed through hydrogenation at adsorption temperature. The C 4 hydrocarbons desorbed at 120 ℃ may be butylidyne. The species desorbed at 320 ℃ are irreversibly adsorbed on the catalyst and difficult to be removed through hydrogenation at adsorption temperature; these species are associated with the deactivation of the catalysts. Oligomers involved in TPSR vary their desorption temperature between 120～360 ℃ with conditions of butadiene adsorption and the catalysts. The products of TPSR on the passivated Mo 2N, compared with the fresh catalyst, show a larger amount of products formed from the cracking and polymerization. Two models of active sites are proposed to explain the difference of TPSR between the fresh and the passivated Mo 2N.

关 键 词：氮化钼 丁二烯 程序升温表面反应 催化剂 

分 类 号：O643[理学—物理化学]