介质阻挡放电去除甲醛的密度泛函分析  

A DFT study on formaldehyde reduction in dielectric barrier discharges

作　　者：王晓静[1] 孙才新[1] 

机构地区：[1]重庆大学输配电及系统安全与新技术国家重点实验室,重庆400044

出　　处：《重庆大学学报（自然科学版）》2010年第11期46-52,共7页Journal of Chongqing University

基　　金：重庆市自然科学基金资助项目(2007BB7172);输配电装备及系统安全与新技术国家重点实验室项目(2007DA10512709303)

摘　　要：采用密度泛函理论对大气压介质阻挡放电非平衡等离子体脱除甲醛进行了研究,建立了反应相对能的计算模型。计算结果证明介质阻挡放电等离子体是常压室温下去除甲醛污染的有效方法,甲醛与OH·、O·和H·等初级自由基的反应均是放热的和热力学有利的过程。O·的主要产生途径是O2直接分解和O2先附着分解再释放电子的过程;通过H2O分解和附着是生成H·和OH·的主要过程;HO2·生成反应中只有2H2O→H2O2+H2是热力学禁阻的反应;HO2·与其他自由基的反应过程均是热力学有利的。通过将笔者的计算结果与以前的实验和理论研究结果对比显示采用密度泛函理论研究介质阻挡放电去除甲醛污染的机理是可行的,说明该方法是对实验的有效和可靠补充。Density functional theory（DFT）is used to study the thermodynamics of formaldehyde removal under dielectric barrier discharges（DBD）non-thermal plasma（NTP）conditions at atmospheric pressure and ambient temperature.A calculation model is defined.The calculated reaction relative energies in this work confirm that the DBD plasma is effective for formaldehyde reduction at ambient conditions and at 1 atm.Present calculations indicate that the reactions of HCHO with primary free radicals such as OH·,O·,and H· are all thermodynamically favored.Moreover,theoretical results show that the main routes of O radical generation from O2 are direct dissociation and dissociative attachment-releasing electron,and the main pathways of H·and OH·from H2O are dissociation and attachment.The only thermodynamic obstacle to HO2· formation is 2H2O→H2O2＋H2.The reactions of HO2· with other radicals are all thermodynamically favored.Comparative results between the previous investigation and the present work demonstrate that theoretical calculation with DFT can be an efficient and reliable supplement for experimental research.

关 键 词：密度泛函理论 介质阻挡放电 低温等离子体 甲醛 反应相对能 热力学 

分 类 号：X511[环境科学与工程—环境工程]