纳米Pt/TiO_2催化剂上气相CH_3OH光催化分解制氢反应的研究  

Study on the Photo-catalytic Decomposition of Methanol Vapor on Pt-loaded Nano-TiO_2 Particles

作　　者：崔文权[1,2] 冯良荣[1] 徐成华[1] 吕绍洁[1] 邱发礼[1] 

机构地区：[1]中国科学院成都有机化学研究所 [2]b中国科学院研究生院北京100039

出　　处：《化学学报》2005年第3期203-209,共7页Acta Chimica Sinica

基　　金：中国科学院与攀枝花市科技成果联合孵化基金(No. SP2002-2)资助项目

摘　　要：利用不同还原方法制备了不同纳米粒度的 Pt/TiO2光催化剂, 并且用脉冲氢氧滴定法测定了 TiO2表面 Pt 的分散度. 在气相连续流动装置中利用纳米 Pt/TiO2作为光催化剂, 对气相甲醇的脱氢反应进行了研究. 研究了添加 Pt 和不添加 Pt 的纳米 TiO2, Pt 负载量、铂的不同还原方法、不同 TiO2纳米粒度对气相甲醇光催化分解反应的影响, 并对反应气的空速、光照时间、添加水蒸汽、改变甲醇浓度等与光催化分解甲醇制氢的关系进行了研究, 在最佳反应条件下, 产氢速率达到 5.808 mmol/(g?h). 研究了反应的动力学, 得到该反应为一级反应, 求得了该反应的活化能为 8.53 kJ/mol,并讨论了反应机理.In the present work, different nano-sized Pt/TiO2 was prepared, and the dispersity of Pt on the surface of TiO2 was measured by hydrogen and oxygen pulse titration method. The photocatalytic decomposition of gaseous methanol on Pt/TiO2 was carried out in a continuous-flow reactor. The effect of various factors on the photocatalysis process was investigated, such as the amount of Pt, different reduction method, different nano-size of TiO2, space velocity, illuminating time, addition of water vapor, methanol concentration, and also the photocatalytic activities of Pt/TiO2 were compared with those of TiO2. One order reaction for methanol decomposition was obtained through the results of kinetics and the activity energy was 8.53 kJ/mol. The reaction mechanism was deduced according to the kinetic and GC/MS analytical results.

关 键 词：甲醇 气相 制氢 光催化分解 最佳反应条件 光催化剂 纳米 PT/TIO2 CH3OH 活化能 

分 类 号：O643.3[理学—物理化学]