Fierro-Gonzalez Juan C, Gates Bruce C
Department of Chemical Engineering and Materials Science, University of California, Davis, California 95616, USA.
J Phys Chem B. 2005 Apr 21;109(15):7275-9. doi: 10.1021/jp050318j.
Mononuclear gold complexes bonded to TiO(2) were synthesized from Au(CH(3))(2)(C(5)H(7)O(2)), and their decomposition and conversion into gold nanoclusters on the TiO(2) surface were characterized by time-resolved X-ray absorption and infrared spectroscopies as the temperature of the sample in flowing helium was ramped up. Mass spectra of the evolved gases were also measured during this process. The results show (a) the onset of formation of CH(4) as a decomposition product, (b) the reduction of Au(III) to Au(0), and (c) the formation of Au-Au bonds, all occurring in approximately the same temperature range (about 335-353 K), indicating that the reduction and aggregation of the supported gold are simultaneous processes facilitated by the removal of methyl ligands initially bonded to the gold. IR spectra recorded during the treatment indicate that water on the TiO(2) surface may be involved in the process by reacting with methyl groups bonded to Au(III) to give CH(4).
由Au(CH(3))(2)(C(5)H(7)O(2))合成了键合到TiO(2)上的单核金配合物，并通过时间分辨X射线吸收光谱和红外光谱对其在流动氦气中升温时在TiO(2)表面的分解以及转化为金纳米团簇的过程进行了表征。在此过程中还测量了逸出气体的质谱。结果表明：（a）作为分解产物的CH(4)开始形成；（b）Au(III)还原为Au(0)；（c）Au-Au键形成，所有这些都发生在大约相同的温度范围（约335 - 353 K）内，这表明负载型金的还原和聚集是由最初键合到金上的甲基配体的去除所促进的同时发生的过程。处理过程中记录的红外光谱表明，TiO(2)表面的水可能通过与键合到Au(III)上的甲基反应生成CH(4)而参与该过程。
