Enhanced Interfacial H-2 Activation for Nitrostyrene Catalytic Hydrogenation over Rutile Titania-Supported Gold by Coadsorption: A First-Principles Microkinetic Simulation Study
Enhanced Interfacial H-2 Activation for Nitrostyrene Catalytic Hydrogenation over Rutile Titania-Supported Gold by Coadsorption: A First-Principles Microkinetic Simulation Study
复制标题
通过共吸附增强金红石二氧化钛负载金上硝基苯乙烯催化氢化的界面 H-2 活化：第一性原理微动力学模拟研究
DOI：
10.1021/acscatal.9b02634
复制
发表时间：
2019
期刊：
影响因子：
12.9
通讯作者：
Hu P.
中科院分区：
文献类型：
--
作者：
Shao Zheng-jiang;Zhang Lidong;Liu Huihui;Cao Xiao-Ming;Hu P.
苯胺是化学工业中非常重要的中间体，芳香族硝基化合物的加氢反应是制备苯胺的有效途径。然而，在硝基芳烃中存在其他可还原基团的情况下，制备一种具有高活性和选择性的催化剂仍然是一个很大的挑战。Au/ tio2催化剂对含有可还原官能团的硝基芳烃的加氢反应具有良好的选择性。然而，他们的活跃度仍然不高。他们还缺乏基本的和系统的认识。本文采用第一性原理非均相微动力学模拟方法研究了Au/ tio2二元界面上4-硝基苯乙烯（4-NS）加氢体系的催化动力学。针对具有非均质多位点的复杂微动力学模型，提出了一种有效的混合迭代数值求解方法，并利用该方法克服了刚性问题。通过实际第一性原理计算和微动力学分析，确定了Au/ tio2界面上4-NS加氢的有利吸附构型和可能的催化机理。研究发现，4-硝基苯乙烯的化学吸附可以显著降低界面处h2解离的能垒，从而提高Au/ tio2催化剂的整体活性。揭示了一种通过调节暴露表面阳离子的配位来促进金属氧化物负载金催化剂选择性加氢活性的方法。
Hydrogenation of aromatic nitro compounds is an efficient way to yield aniline, an extremely vital intermediate in many chemical industry fields. However, it is still a great challenge to prepare a catalyst with both high activity and selectivity for this important process when other reducible groups exist at nitroaromatics. Au/TiO2catalysts could achieve good selectivity for the hydrogenation of nitroarenes with a reducible functional group. However, their activity is still not high. Their fundamental and systematic understandings are still lacking. In this work, the catalytic kinetics of the 4-nitrostyrene (4-NS) hydrogenation system at the binary Au/TiO2interface is investigated by first-principles heterogeneous site microkinetics simulation. To solve the complex microkinetics model with heterogeneous multiple sites, an efficient hybrid iteration numerical method is proposed and utilized to overcome the stiff problem. Through realistic first-principles calculations and microkinetic analysis, the favorable adsorption configurations and possible catalytic mechanism are determined for 4-NS hydrogenation at the Au/TiO2interface. It is found that the chemisorption of 4-nitrostyrene could significantly lower the energy barrier of H2dissociation at the interface, which could enhance the overall activity of the Au/TiO2catalyst. It sheds light on a way to promote the activity of selective hydrogenation for metal oxide-supported gold catalysts through modulating the coordination of exposed surface cations.