Wu Zewen, Ma Shenggui, Weng Shuxian, Liu Hongying, Jin Ziheng, Jiang Xia
College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China.
ACS Appl Mater Interfaces. 2024 Jul 24;16(29):38111-38123. doi: 10.1021/acsami.4c07453. Epub 2024 Jul 15.
The catalytic deoxygenation of phenolic compounds is a crucial step in the valorization of biomass resources, which can effectively enhance the heating value and stability of primary biofuel. In this study, the catalytic mechanism of four Heusler alloy catalysts for the direct deoxidation pathway of phenol was studied through electronic structure regulation by element occupation. We found that Heusler alloys catalysts exhibit excellent catalytic activity in the dissociation activation of H and the cleavage of aryl hydroxyl bond (C-OH) bonds. The energy barriers for the direct cleavage of the C-OH bond in phenol on NiMoAl, CoMoAl, NiNbAl and NiMoGa catalysts are 0.86, 0.95, 1.09, and 1.28 eV, respectively. And Y element of the XYZ catalyst has a significant impact on this reaction, while the X element has a complex influence on the hydrogenation step of the unsaturated benzene ring. Microkinetic analysis further substantiates that the phenol (C-OH) bond cleavage step in the reaction exhibits a fast reaction rate and high extent of reaction. The reaction of hydroxyl hydrogenation to produce water exhibits the highest energy barrier, serving as the rate-determining step of the entire reaction. This issue could potentially be addressed by further fine-tuning the electronic structure.
酚类化合物的催化脱氧是生物质资源增值的关键步骤，可有效提高初级生物燃料的热值和稳定性。在本研究中，通过元素占位调控电子结构，研究了四种赫斯勒合金催化剂对苯酚直接脱氧途径的催化机理。我们发现，赫斯勒合金催化剂在H的解离活化和芳基羟基键（C-OH）的断裂方面表现出优异的催化活性。苯酚在NiMoAl、CoMoAl、NiNbAl和NiMoGa催化剂上直接断裂C-OH键的能垒分别为0.86、0.95、1.09和1.28 eV。并且XYZ催化剂中的Y元素对该反应有显著影响，而X元素对不饱和苯环的氢化步骤有复杂影响。微观动力学分析进一步证实，反应中苯酚（C-OH）键断裂步骤表现出快速的反应速率和较高的反应程度。羟基氢化生成水的反应具有最高的能垒，是整个反应的速率决定步骤。这个问题可能通过进一步微调电子结构来解决。
