Identification of active sites in gold-catalyzed hydrogenation of acrolein.
Identification of active sites in gold-catalyzed hydrogenation of acrolein.
复制标题
DOI：
10.1021/ja027321q
复制
发表时间：
2003-01
影响因子：
15
通讯作者：
C. Mohr;H. Hofmeister;J. Radnik;P. Claus
中科院分区：
文献类型：
--
作者：
C. Mohr;H. Hofmeister;J. Radnik;P. Claus
负载型金催化剂的活性位点，有利于吸附的C=O基团的丙烯醛和随后的反应烯丙醇，已被确定为金纳米粒子的边缘。我们最近发现，这种反应优先发生在单晶颗粒，而不是多孪晶的，本文报道了一种新的方法来区分不同的功能的金颗粒形态。活性位点问题的阐明不能简单地通过改变金颗粒的尺寸来完成，因为小面化和多重孪生颗粒的影响可能会干扰。因此，通过铟对金颗粒表面的改性已被用于改变合适催化剂的活性位点特性，并且已观察到金颗粒表面的选择性装饰，留下边缘自由。这与理论预测相矛盾，表明金粒子的低配位边缘优先占据。在双相催化剂上，所需的烯丙醇是主要产物（选择性63%;温度593 K，总压力p（总）= 2 MPa）。从实验证明的表面结构和催化行为之间的相关性，单晶金颗粒的边缘已被确定为优选的C=O氢化的活性位点。
The active sites of supported gold catalysts, favoring the adsorption of C=O groups of acrolein and subsequent reaction to allyl alcohol, have been identified as edges of gold nanoparticles. After our recent finding that this reaction preferentially occurs on single crystalline particles rather than multiply twinned ones, this paper reports on a new approach to distinguish different features of the gold particle morphology. Elucidation of the active site issue cannot be simply done by varying the size of gold particles, since the effects of faceting and multiply twinned particles may interfere. Therefore, modification of the gold particle surface by indium has been used to vary the active site characteristics of a suitable catalyst, and a selective decoration of gold particle faces has been observed, leaving edges free. This is in contradiction to theoretical predictions, suggesting a preferred occupation of the low-coordinated edges of the gold particles. On the bimetallic catalyst, the desired allyl alcohol is the main product (selectivity 63%; temperature 593 K, total pressure p(total) = 2 MPa). From the experimentally proven correlation between surface structure and catalytic behavior, the edges of single crystalline gold particles have been identified as active sites for the preferred C=O hydrogenation.