Effect of Sulfate Adlayer on Formic Acid Oxidation on Pd(111) Electrode  

硫酸(氢)根吸附层对Pd(111)电极上甲酸氧化反应的影响研究（英文）

作　　者：Jing Lei Zhen Wei Mian-le Xu Jie Wei Yan-xia Chen Shen Ye 雷晶;韦臻;许绵乐;魏杰;陈艳霞;叶深(中国科学技术大学化学物理系,合肥微尺度物质科学国家研究中心,合肥230026;日本东北大学化学系,科学研究院,仙台)

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale,Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China [2]Department of Chemistry,Graduate School of Science,Tohoku University,Sendai,Japan

出　　处：《Chinese Journal of Chemical Physics》2019年第6期649-656,I0002,共9页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China(No.21872132 and No.21832004);973 Program from the Ministry of Science and Technology of China(No.201503932301)

摘　　要：The kinetics of formic acid oxidation (FAO) on Pd(111) in 0.1 mol/L H2SO4+0.1 mol/L HCOOH with and without addition of Na2SO4 is studied using cyclic voltammetry and potential step method, which is compared with that in 0.1 mol/L HClO4. It is found that adsorbed sulfate has significant inhibition effect on FAO kinetics. After addition of 0.05 mol/L or 0.1 mol/L Na2SO4, FAO current in the negative-going scan is found to be significantly smaller than that at the same potential in the positive-going scan. We speculate that at potentials positive of the phase transition potential for the (SO4*ad)m+[(H2O)n-H3O+] or(SO4*ad)m+[Na+(H2O)n-H3O+] adlayer, the adlayer structure probably becomes denser and more stable with the increase of potential or with the addition of Na2SO4. The formation of connected adlayer network greatly enhance the stability of the adlayer, and the insertion of positive-charged H+ or Na+ into the adlayer network further reduces the electrostatic repulsion between partially charged sulfates. As a result, the destruction/desorption of compact sulfate adlayer becomes more difficult, which leaves much less free sites on the surface for FAO, and thus FAO kinetics at higher potentials and in the subsequent negative-going potential scan is significantly inhibited.

关 键 词：Formic acid oxidation Pd(111) electrode Sulfate adsorption Anions effect 

分 类 号：O643.36[理学—物理化学] TM91[理学—化学]