Effect of strong metal–support interaction on the catalytic performance of Pd/TiO2 in the liquid-phase semihydrogenation of phenylacetylene
Effect of strong metal–support interaction on the catalytic performance of Pd/TiO2 in the liquid-phase semihydrogenation of phenylacetylene
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DOI：
10.1016/j.jcat.2008.12.011
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发表时间：
2009-03
影响因子：
7.3
通讯作者：
Patcharaporn Weerachawanasak;O. Mekasuwandumrong;M. Arai;S. Fujita;P. Praserthdam;J. Panpranot
中科院分区：
文献类型：
--
作者：
Patcharaporn Weerachawanasak;O. Mekasuwandumrong;M. Arai;S. Fujita;P. Praserthdam;J. Panpranot
在9 ~ 23 nm范围内的不同tio2晶粒尺寸的溶剂热衍生纳米tio2负载Pd催化剂上，研究了苯乙炔在温和条件下的液相半加氢反应。CO化学吸附和透射电镜结果表明，所有催化剂在500℃还原时均表现出较强的金属-载体相互作用（SMSI）。在苯乙炔完全转化过程中，SMSI催化剂的加氢活性（周转频率为9.1 ~ 21.4 s−1）和对苯乙烯的中高选择性（86 ~ 90%）均表现出优异的催化性能。在没有SMSI效应的情况下（催化剂在40℃下还原），苯乙烯选择性和催化活性很大程度上取决于Pd颗粒的大小，其中小Pd颗粒（在小晶粒尺寸的tio2载体上形成）表现出较低的苯乙炔转化率和较差的苯乙烯选择性。此外，非smsi催化剂的TOF值与文献报道的其他负载型钯催化剂在温和条件下对苯乙炔进行液相半加氢时的TOF值相似（TOF值为1.3 ~ 2.8 s−1）。
Liquid-phase semihydrogenation of phenylacetylene under mild conditions has been investigated on a series of solvothermal-derived nano-TiO2supported Pd catalysts with various TiO2crystallite sizes in the range of 9–23 nm. As revealed by CO chemisorption and transmission electron microscopy, all the catalysts exhibited strong metal–support interaction (SMSI) when reduced at 500 °C. The catalysts with SMSI show remarkably high catalytic performance in terms of both hydrogenation activities (turnover frequencies (TOFs) 9.1–21.4 s−1) and moderate-high selectivities to styrene (86–90%) at complete conversion of phenylacetylene. Without SMSI effect (the catalysts reduced at 40 °C), styrene selectivity and catalytic activity depended largely on the Pd particle size in which small Pd particles (formed on small crystallite size TiO2supports) exhibited lower phenylacetylene conversion and poor styrene selectivity. Moreover, the TOF values of the non-SMSI catalysts were similar to those reported in the literature for other supported Pd catalysts in liquid-phase semihydrogenation of phenylacetylene under mild conditions (TOFs 1.3–2.8 s−1).