H_(2)O_(2)/Fe_(2)(MoO_(4))_(3)体系中H_(2)O_(2)吸附分解及NO氧化行为的DFT研究  

DFT investigation on H_2O_(2) adsorption,decomposition and NO oxidation behaviors in H_2O_2/Fe_2(MoO_4)_(3) system

作　　者：刘璇 吕强[3] 王长安[3] 车得福[3] 李彩亭[1,2] LIU Xuan;LYU Qiang;WANG Chang′an;CHE Defu;LI Caiting(College of Environmental Science and Engineering,Hunan University,Changsha410082,China;Key Laboratory of Environmental Biology and Pollution Control(Hunan University),Ministry of Education,Changsha410082,China;State Key Laboratory of Multiphase Flow in Power Engineering,Xi′an Jiaotong University,Xi′an710049,China)

机构地区：[1]湖南大学环境科学与工程学院,湖南长沙410082 [2]环境生物与控制教育部重点实验室(湖南大学),湖南长沙410082 [3]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《洁净煤技术》2023年第10期82-90,共9页Clean Coal Technology

基　　金：国家自然科学基金资助项目(52300159);湖南省自然科学基金资助项目(2022JJ40071)。

摘　　要：为阐明H_(2)O_(2)/Fe_(2)(MoO_(4))_(3)体系脱硝过程中H_(2)O_(2)吸附分解及NO氧化行为,基于DFT方法首次计算了H_(2)O_(2)和NO分子单独及二者同时在Fe_(2)(MoO_(4))_(3)表面的吸附构型,并通过考察吸附能、Mulliken电荷及氧化路径等特性揭示H_(2)O_(2)催化分解和NO氧化的微观机制。结果表明:H_(2)O_(2)在Fe_(2)(MoO_(4))_(3)表面易分解为活性自由基,而NO则以分子形式吸附;H_(2)O_(2)和NO共吸附时,H_(2)O_(2)优先吸附于催化剂表面并随后分解,NO则分别被H_(2)O_(2)分解产生的OH/O基团氧化为HNO_(2)/NO_(2);氧化产物HNO_(2)和NO_(2)仅通过氢键与催化剂表面作用,易在流体扰动下进入主流烟气,从而降低了催化剂表面硝酸盐沉积的可能性。本研究阐明了Fe_(2)(MoO_(4))_(3)催化剂表面H_(2)O_(2)吸附分解及NO氧化的微观机制,为设计兼具高催化活性及优良稳定性的非均相类Fenton脱硝体系提供理论指导。To elucidate the adsorption/decomposition behavior of H_2O_(2) and oxidation behavior of NO in H_2O_2/Fe_2(MoO_4)_(3) denitrification system,density functional theory(DFT) calculations were performed to investigate the individual adsorption and co-adsorption characteristics of H_2O_(2) and NO on Fe_2(MoO_4)_(3) surface for the first time.The adsorption energies,Mulliken population,and oxidation pathways were systematically analyzed to reveal the mechanism of catalytical decomposition of H_2O_(2) and NO oxidation.The results show that H_2O_(2) can be easily decomposed into reactive radicals on Fe_2(MoO_4)_(3) surface,while NO is adsorbed in molecular form.In the case of co-adsorption,H_2O_(2) preferentially adsorbs on the catalyst surface and undergoes decomposition process.NO is subsequently oxidized to HNO_2/NO_(2) by the hydroxyl group/oxygen atom generated from H_2O_(2) decomposition.The oxidation products HNO_2/NO_(2) are only bonded to the catalyst surface via hydrogen bond and can easily enter the mainstream flue gas under flow disturbance,thus reducing the deposition possibility of nitrate on catalyst surface.This study unravels the micro mechanism of H_2O_(2) adsorption/decomposition and NO oxidation on Fe_2(MoO_4)_(3) surface,providing theoretical guidance for designing heterogeneous Fenton-like denitrification system with high catalytic activity and excellent stability.

关 键 词：DFT NO H_(2)O_(2)分解 脱硝 吸附 氧化机制 

分 类 号：TK16[动力工程及工程热物理—热能工程]