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首页> 外文期刊>Physical chemistry chemical physics: PCCP >Theoretical insights into the effect of the overpotential on CO electroreduction mechanisms on Cu(111): regulation and application of electrode potentials from a CO coverage-dependent electrochemical model
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Theoretical insights into the effect of the overpotential on CO electroreduction mechanisms on Cu(111): regulation and application of electrode potentials from a CO coverage-dependent electrochemical model

机译：对Cu（111）CO电荷机制的超态对CO（111）的影响的理论见解：CO覆盖依赖电化学模型的调节和应用

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摘要

A recently proposed CO coverage-dependent electrochemical model combined with the calculation of electronic structure is applied for the first time to study the effect of the overpotential on Cu-catalyzed CO electroreduction mechanisms by changing the coverage of surface adsorbed CO. The results show that the presently defined CH2O and CHOH pathways may be able to occur parallelly under different overpotentials. However, high overpotentials will facilitate CO electroreduction, thus explaining why a high overpotential is required during CO2 electroreduction in experiments on Cu electrodes. The potential-limiting step may be further CO electroreduction into CHO, which is considered as the origin of the experimentally observed high overpotentials. The analyses of electronic structure show that an adsorbed CO delta- species is formed on the Cu electrodes, validating the previous experimental speculations on electron transfer between CO and Cu electrodes. More and more electrons are transferred into the pi antibonding orbitals of the adsorbed CO with increasing surface CO coverage, leading to increasing overpotential and weaker and weaker CO bonding with the Cu surface. Thus, the significantly lower barrier of further CO electroreduction at higher overpotential can be correlated with lower CO adsorption energy. Interestingly, it is found that there is greater localization of electrons around the C than the O atom in the adsorbed CO molecule, explaining why the hydrated proton prefers to reach the C atom to form intermediate CHO rather than COH.
机译：最近提出的CO覆盖依赖性电化学模型与电子结构的计算相结合，首次应用了通过改变表面吸附的CO的覆盖率来研究超全电流对Cu催化CO电荷电池的影响。结果表明了目前定义的CH2O和CHOH途径可以在不同的过电位下并行发生。然而，高过电位将有助于CO电控制，从而解释为什么在Cu电极的实验中的CO2电荷中需要高过电位。潜在限制的步骤可以进一步将CHO电耦合到CHO，其被认为是实验观察到的高过电位的起源。电子结构的分析表明，在Cu电极上形成吸附的Coδ，验证了对CO和Cu电极之间的电子传递的先前实验赌注。随着表面CO覆盖的增加，越来越多的电子转移到吸附的CO的PI抗抗体轨道中，导致增加过电位和较弱，与Cu表面粘合较弱。因此，在较高的过电位下进一步CO电荷的显着较低屏障可以与较低的CO吸附能量相关。有趣的是，发现C围绕CO分子中的O原子围绕C的电子局部定位，解释了水合的原子更喜欢到达C原子以形成中间CHO而不是COH。

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    Ou Lihui; Chen Junxiang;

  • 作者单位

    Hunan Univ Arts &

    Sci Coll Chem &

    Mat Engn Hunan Prov Cooperat Innovat Ctr Construct &

    Dev D Changde 415000 Peoples R China;

    Chinese Acad Sci CAS Key Lab Design &

    Assembly Funct Nanostruct Fujian Prov Key Lab Nanomat Fujian Inst Res Struct Matter Fuzhou 350002 Peoples R China;

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  • 正文语种 eng
  • 中图分类 物理学;化学;
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