醇类在Pt-TiO_2纳米管上的光催化制氢

Hydrogen production by alcohols photocatalysis on Pt-TiO_2/nanotubes

采用溶胶-凝胶法(sol-gel)、水热法和光沉积法制备了铂(Pt)负载量为0.5%的二氧化钛纳米管催化剂(TNT),并利用甲醇等醇类制氢。结果表明,所制备的催化剂具有良好的管状形貌;甲醇(CH3OH)和水在同等数量级上共同吸附在催化剂表面9h后制氢效率最高,核磁共振氢谱(1 H NMR)分析表明甲醇裂解制氢过程在催化剂表面进行,因氢键束缚产生的过渡产物无法脱附直至形成CO2;醇类碳链长度、支链数目、羟基数目以及苯环基团等都对醇类制氢有着不同的影响,制氢过程中醇分子与催化剂的吸附作用强弱和醇分子被羟基植入的难易程度是制氢效果差异的主要原因。

Sol-gel,hydrothermal and photoassisted platinum deposition methods were used to prepare Pt（0.5%）-TiO2/nanotube catalysts.The results show that catalysts are of ideal tubular morphology and large specific surface area.The highest efficiency of hydrogen production appears when the co-adsorption of methanol and water on the catalyst is at the same order of magnitude after 9 h.The results obtained by 1H NMR reveal that methanol molecules are cracked on the catalyst surface,and the transitional products can not be desorbed because of the shackles of hydrogen bonds until CO2 formation.The length of carbon chain,number of branched chains,number of —OH and benzene ring groups on alcohol molecules are of different effects on hydrogen production.The strong or weak adsorption of alcohols on catalysts,and easy or difficult hydroxyl implantation into alcohol molecules can be used to explain these differences.