Choudhury Debittree, Das Rubul, Maurya Rajan, Gupta Geetanksha, Neergat Manoj
Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Phys Chem Chem Phys. 2023 Apr 12;25(15):10966-10976. doi: 10.1039/d3cp00047h.
Low-frequency () inductive features in the impedance spectra of electron-transfer reactions at the electrode-electrolyte interface in acidic and alkaline media are investigated. The trend in equivalent circuit () parameters (inductor () and series resistance ()) is analysed as a function of overpotential for the two widely investigated electrochemical reactions, ., methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR). The decreasing trend in the parameter values of the reactions not limited by mass-transport (such as the MOR) and that in the mixed kinetic-diffusion controlled region for mass-transport limited reactions (ORR) are attributed to the faster surface relaxation with applied overpotential, whereas the increase of the and values in the mass-transport limiting region in an acidic medium is shown to originate from the extra hindrance caused by the limited supply of reactant species. Such analysis of parameters with overpotential is important to understand the underlying physical processes and to establish equivalent circuit models.
研究了酸性和碱性介质中电极 - 电解质界面电子转移反应阻抗谱中的低频（）电感特征。分析了两个广泛研究的电化学反应（即甲醇氧化反应（MOR）和氧还原反应（ORR））的等效电路（）参数（电感（）和串联电阻（））随过电位的变化趋势。不受传质限制的反应（如MOR）的参数值下降趋势以及传质受限反应（ORR）在混合动力学 - 扩散控制区域的下降趋势归因于施加过电位时更快的表面弛豫，而在酸性介质中传质限制区域和值的增加表明源于反应物物种供应有限所造成的额外阻碍。对参数随过电位的这种分析对于理解潜在的物理过程和建立等效电路模型很重要。
