乙醇在Pt低指数晶面吸附的密度泛函理论研究  

Theoretical Study on DFT of Ethanol Adsorption on Pt Low-Index Surfaces

作　　者：景晓环 郭瑞华[1,2,3] 安胜利 张捷宇[3] 周国治 李慧琴[1] Jing Xiaohuan;Guo Ruihua;An Shengli;Zhang Jieyu;Zhou Guozhi;Li Huiqin(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Inner Mongolia Key Laboratory of Advanced Ceramic Materials and Devices,Baotou 014010,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200072,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]内蒙古自治区先进陶瓷材料与器件重点实验室,内蒙古包头014010 [3]上海大学材料科学与工程学院,上海200072

出　　处：《稀有金属》2022年第2期206-214,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51864040,51974167);内蒙古自治区自然科学基金项目(2018LH02006)资助。

摘　　要：基于范德华校正的密度泛函理论(DFT-D3),通过优化乙醇几何参数,计算Pt低指数晶面上的吸附能、态密度、功函数和Bader电荷,系统研究了乙醇在Pt低指数晶面上的吸附过程。结果表明,乙醇分子到Pt(110)晶面的距离最小,相互作用最强;乙醇在Pt低指数晶面上的吸附能顺序为Pt(110)>Pt(100)>Pt(111);通过态密度的计算分析发现,吸附后乙醇的Op轨道向负方向偏移,且偏移程度与吸附能大小一致,其中在Pt(110)晶面上的偏移程度最大;Pt(100)和Pt(110)晶面吸附乙醇后功函数变化值接近,Pt(111)晶面变化最小;Bader电荷分析表明,乙醇在Pt各晶面上的净电荷转移量接近,其中在Pt(110)晶面上电荷转移最大。通过以上理论计算发现,Pt(110)晶面对乙醇的吸附作用最强,说明此晶面对乙醇的催化活性最强,本计算可为设计开发乙醇催化氧化的高效催化剂提供理论支持。At present,the rapid development of the national industrialization had caused serious environmental pollution problems,and the increasing shortage of fossil fuels such as coal,oil and natural gas had made the development of clean and environment-friendly energy extremely urgent.Nowadays,direct ethanol fuel cell(DEFC)has received widespread attention due to its advantages in environmental protection and renewable energy.DEFC usually used ethanol as fuel,it did not go through the Carnot cycle and could directly convert chemical energy into electrical energy without any intermediate steps.In addition,because ethanol is non-toxic,easy to store,and perfect in industrial production technology,DEFC had become a renewable energy.Compared with internal combustion engines,DEFC had higher energy efficiency and less greenhouse gas emissions,which made it had a relatively high efficiency.Therefore,a new type of low-polluting green energy had received massive attention and it was very likely to become a substitute for fossil energy.However,DEFC also had a few shortcomings.First of all,in an ideal state,ethanol was completely oxidized at the anode of DE-FC to produce CO_(2)and protons,but under actual working conditions,it was extremely difficult to break the C-C bond of ethanol,meanwhile,various intermediate products produced during the oxidation of ethanol were easily adsorbed on the surface of catalyst,which occupied the active sites of the catalyst,resulting in low efficiency of ethanol oxidation.Secondly,the main reason for limiting the commercialization of DEFC was that the most widely used traditional noble metal catalysts were expensive and the catalytic efficiency needs to be improved.Therefore,in order to improve the efficiency of catalytic oxidation of ethanol,scholars at home and abroad had prepared Pt catalysts with different preferred orientations to explore the effect of Pt catalysts on the catalytic performance of ethanol.However,the mechanism of improving its catalytic performance was still unclear,and theoreti

关 键 词：密度泛函理论 乙醇 Pt低指数晶面 吸附 

分 类 号：TM911.4[电气工程—电力电子与电力传动]