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本文介绍了在温和条件下,AuCl_3-KBH_4-H_2O 催化体系对乙炔的选择性加氢活性及其动力学规律的考察。同位素探针实验表明:加氢过程的氢源由 KBH_4和 H_2O 共同提供;还原反应系顺式加成;乙烯从乙炔直接生成。通过原子发射光谱、X 光衍射、光电子能谱分析以及分子轨道理论计算证实:催化活性中心为金原子,乙炔分子在金原子上的侧基络合是其活化状态.在17°～30℃范围内求出乙炔加氢为乙烯和乙烷的表现活化能分别是23.5与42.6KJ·mol~(-1).根据实验结果,提出一个初步的反应机理.
In this paper, the selective hydrogenation activity of acetylene in AuCl_3-KBH_4-H_2O catalytic system under mild conditions and its kinetics are reviewed. Isotope probe experiments show that: the hydrogen source hydrogenation process by KBH_4 and H_2O co-supply; reduction reaction cis-addition; ethylene directly from acetylene. It was confirmed by atomic emission spectroscopy, X-ray diffraction, photoelectron spectroscopy and molecular orbital theory calculations that the active center of the catalyst is gold atom and the side-group complexation of acetylene molecule on the gold atom is the activation state. In the range of 17 ° -30 ° C The results showed that the activation energies of acetylene hydrogenation to ethylene and ethane were 23.5 and 42.6 KJ · mol -1, respectively. Based on the experimental results, a preliminary reaction mechanism was proposed.