Sonochemical Hydrogen Production Efficiently Catalyzed by Au/TiO2

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• 作者：Yifeng Wang ; Dan Zhao ; Hongwei Ji ; Guilin Liu ; Chuncheng Chen ; Wanhong Ma ; Huaiyong Zhu ; Jincai Zhao
• 刊名：Journal of Physical Chemistry C
• 出版年：2010
• 出版时间：October 21, 2010
• 年：2010
• 卷：114
• 期：41
• 页码：17728-17733
• 全文大小：191K
• 年卷期：v.114,no.41(October 21, 2010)
• ISSN：1932-7455

文摘

Au/TiO₂ was used as a highly efficient sonocatalyst to produce H₂ from water or aqueous solutions. Au/TiO₂ significantly increased the yields of H^• and ^•OH radicals in the sonolysis of water. Product analysis and isotope evidence indicated that hydrogen molecules derived from methanol/water solutions were formed by three pathways: (1) recombination of two H^• atoms from the cleavage of water molecules, (2) H-abstraction from methanol by H^• generated by water cleavage, and (3) thermal reforming of methanol. The relative importance of each pathway was assessed by carefully analyzing the hydrogen-isotope composition of the evolved hydrogen gas using a modified gas chromatograph. The source of hydrogen in the H₂ evolved from methanol/water solutions during sonolysis was also addressed. Data showed that, although the addition of methanol in the presence of Au/TiO₂ resulted in a 12-fold increase in the rate of H₂ evolution, nearly half of the hydrogen atoms were nevertheless derived from water molecules. Control studies of H₂ formation in the presence of bare TiO₂ and in the absence of a catalyst were also performed. In both cases, the compositions of evolved hydrogen gas were similar to that of the Au/TiO₂ system, although hydrogen evolution was much slower. These findings reveal that Au nanoparticles on the TiO₂ surface effectively catalyze water cleavage and methanol reforming.