ZnAl-Hydrotalcite-Supported Au25 Nanoclusters as Precatalysts for Chemoselective Hydrogenation of 3-Nitrostyrene
ZnAl-Hydrotalcite-Supported Au25 Nanoclusters as Precatalysts for Chemoselective Hydrogenation of 3-Nitrostyrene
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ZnAl-水滑石负载的 Au-25 纳米团簇作为 3-硝基苯乙烯化学选择性氢化的预催化剂
DOI：
10.1002/anie.201610736
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发表时间：
2017-03-01
影响因子：
16.6
通讯作者：
Zhang, Tao
中科院分区：
文献类型：
--
作者：
Tan, Yuan;Liu, Xiao Yan;Zhang, Tao
3-硝基苯乙烯化学选择性加氢成3-乙烯基苯胺是一项具有挑战性的研究，因为在大多数贵金属催化剂上，乙烯基和硝基会竞争性活化。一种由硫代Au-25纳米团簇组成的预催化剂负载在锌-水滑石上，即使在500℃下煅烧，也能得到尺寸可控的金催化剂（约2.0 nm）。该催化剂对3-乙烯苯胺表现出优异的选择性（约98%），并在较宽的反应时间和温度范围内完全转化3-硝基苯乙烯。这一结果对于金催化剂来说是前所未有的。对照实验和衰减全反射红外光谱结果表明，与传统催化剂相比，金催化剂对乙烯基是惰性的，只对硝基是活性的。这一发现可以推广到设计具有优良化学选择性的金催化剂，用于精细化学品的合成。
Chemoselective hydrogenation of 3-nitrostyrene to 3-vinylaniline is quite challenging because of competitive activation of the vinyl group and the nitro group over most supported precious-metal catalysts. A precatalyst comprised of thiolated Au-25 nanoclusters supported on ZnAl-hydrotalcite yielded gold catalysts of a well-controlled size (ca. 2.0 nm)-even after calcination at 500 degrees C. The catalyst showed excellent selectivity (> 98%) with respect to 3-vinylaniline, and complete conversion of 3-nitrostyrene over broad reaction duration and temperature windows. This result is unprecedented for gold catalysts. In contrast to traditional catalysts, the gold catalyst is inert with respect to the vinyl group and is only active with regard to the nitro group, as demonstrated by the results of the control experiments and attenuated total reflection infrared spectra. The findings may extend to design of gold catalysts with excellent chemoselectivity for use in the synthesis of fine chemicals.