First-principles study on the heterogeneous formation of environmentally persistent free radicals(EPFRs)overα-Fe2O3(0001)surface:Effect of oxygen vacancy  

作　　者：Wenxiao Pan Shuming He Qiao Xue Xian Liu Jianjie Fu Kang Xiao Aiqian Zhang 

机构地区：[1]State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China [2]School of Environment,Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310012,China [3]College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China [4]Beijing Yanshan Earth Critical Zone National Research Station,University of Chinese Academy of Sciences,Beijing 101408,China

出　　处：《Journal of Environmental Sciences》2024年第8期279-289,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21976206,22136001,22276197,92143201);the National Key Research and Development Program of China(No.2020YFA0907500);the Beijing Natural Science Foundation(No.JQ22027)。

摘　　要：Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy(WtE)incineration processes.This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals(EPFRs)from phenolic compounds based on the first-principles calculations.Two oxygen-deficient conditions were considered:oxygen vacancies at the top surface and on the subsurface.Our simulations indicate that the adsorption strength of phenol on theα-Fe_(2)O_(3)(0001)surface is enhanced by the presence of oxygen vacancies.However,the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule,particularly for the surface with a defective point at the top layer.Thermo-kinetic parameters were established over a temperature range of300-1000 K,and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface.The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeⅢto FeⅡ,which lower the oxidizing ability of surface reaction sites.The findings of this study provide us a promising approach to regulate the formation of EPFRs.

关 键 词：EPFR formation Phenol dissociation Oxygen-vacancy impact Hematite surface First-principles calculation 

分 类 号：X705[环境科学与工程—环境工程] TQ138.11[化学工程—无机化工]