Chem. J. Chinese Universities ›› 2020, Vol. 41 ›› Issue (5): 1058.doi: 10.7503/cjcu20190699

• Physical Chemistry • Previous Articles     Next Articles

Electrochemical Spectroscopy Analysis for Kinetics of the CO2 Electroreduction Reaction on Ni Single Atom Catalysts

MAO Qing1,*(),ZHAO Jian1,LIU Song2,GUO Chang1,LI Bingyu1,XU Keyi1,CAO Ziqiang1,HUANG Yanqiang2   

  1. 1. School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China
    2. Laboratory of Aerospace Catalysts and New Materials, Dalian Institute of Chemical Physics,Chinese Academy of Sciences, Dalian 116023, China
  • Received:2019-12-23 Online:2020-05-10 Published:2020-02-21
  • Contact: Qing MAO E-mail:maoqing@dlut.edu.cn
  • Supported by:
    † Supported by the GF Innovation Foundation of Dalian University of Technology, China(DUT18GF308)

Abstract:

Single site mechanism and bi-function mechanism were both put forward for CO2 electro-reduction reaction(CO2RR) on the carbon-nitride anchoring Ni single atoms catalysts. The former is specific to the CO2RR only on the active site Ni and the latter considers both reductions on the Ni site and water spitting on the anchoring carbon nitride site. Kinetic analysis of the CO2RR as well as sensitivity analysis for the model parameters were both performed by means of static CO2RR models and experimental polarizations. Electrochemical impedance spectroscopy(EIS) and total harmonic distortion(THD) spectroscopy were also simulated using dynamic CO2RR models to explore its linear and nonlinear frequency response behaviors, respectively. It is suggested that CO2 concentration is the most sensitive parameters to CO2RR performance. The elemental step to form COOHads is the rate determines step as the CO2RR follows the single site mechanism. As for the bi-function mechanism, both CO2,ads electro-reduction on the Ni site and water splitting on the carbon nitride site are rate-determining steps of the CO2RR. Transient simulation of CO2RR reveals that the EIS is able to tell the difference of the single site mechanism from the bi-function mechanism theoretically over the THD spectroscopy.

Key words: CO2 Electro-reduction reaction(CO2RR) mechanism, Electrochemical impedance spectroscopy(EIS), Nonlinear frequency response analysis, Total harmonic distortion(THD) spectroscopy

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