纳米Pt/TiO2催化剂上气相CH3OH光催化分解制氢反应的研究

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.

Study on the Photo-catalytic Decomposition of Methanol Vapor on Pt-loaded Nano-TiO2 Particles

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 decompo- sition 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 concentra- tion, 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.