State Key Laboratory of Coal Conversion, Institute of Coal Chemistry , Chinese Academy of Sciences , Taiyuan , Shanxi 030001 , China.
University of the Chinese Academy of Sciences , Beijing 100039 , China.
ACS Appl Mater Interfaces. 2018 Jul 11;10(27):23029-23036. doi: 10.1021/acsami.8b04044. Epub 2018 Jun 29.
Efficient catalytic hydrogenation of nitroarenes to anilines with molecular hydrogen at room temperature is still a challenge. In this study, this transformation was achieved by using a photocatalyst of SiC-supported segregated Pd and Au nanoparticles. Under visible-light irradiation, the nitrobenzene hydrogenation reached a turnover frequency as high as 1715 h at 25 °C and 0.1 MPa of H pressure. This exceptional catalytic activity is attributed to a synergistic effect of Pd and Au nanoparticles on the semiconducting SiC, which is different from the known electronic or ensemble effects in Pd-Au catalysts. This kind of synergism originates from the plasmonic electron injection of Au and the Mott-Schottky contact at the interface between Pd and SiC. This three-component system changes the electronic structures of the SiC surface and produces more active sites to accommodate the active hydrogen that spills over from the surface of Pd. These active hydrogen species have weaker interactions with the SiC surface and thus are more mobile than on an inert support, resulting in an ease in reacting with the N═O bonds in nitrobenzene absorbed on SiC to produce aniline.
在室温下，用分子氢高效催化氢化硝基芳烃为苯胺仍然是一个挑战。在这项研究中，使用碳化硅负载的分离钯和金纳米粒子作为光催化剂实现了这种转化。在可见光照射下，硝基苯在 25°C 和 0.1 MPa H 压力下的加氢转化率高达 1715 h-1。这种优异的催化活性归因于 Pd 和 Au 纳米粒子在半导体 SiC 上的协同作用，这与已知的 Pd-Au 催化剂中的电子或整体效应不同。这种协同作用源于 Au 的等离子体电子注入和 Pd 与 SiC 之间界面处的 Mott-Schottky 接触。这种三元体系改变了 SiC 表面的电子结构，并产生更多的活性位，以容纳从 Pd 表面溢出的活性氢。这些活性氢物种与 SiC 表面的相互作用较弱，因此比在惰性载体上更具流动性，从而更容易与吸附在 SiC 上的硝基苯的 N═O 键反应生成苯胺。
