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DOI	10.1039/c9ee02485a
	Modeling the electrical double layer to understand the reaction environment in a CO2 electrocatalytic system
	Bohra D.; Chaudhry J.H.; Burdyny T.; Pidko E.A.; Smith W.A.
发表日期	2019
ISSN	17545692
起始页码	3380
结束页码	3389
卷号	12 期号:11
英文摘要	The environment of a CO2 electroreduction (CO2ER) catalyst is intimately coupled with the surface reaction energetics and is therefore a critical aspect of the overall system performance. The immediate reaction environment of the electrocatalyst constitutes the electrical double layer (EDL) which extends a few nanometers into the electrolyte and screens the surface charge density. In this study, we resolve the species concentrations and potential profiles in the EDL of a CO2ER system by self-consistently solving the migration, diffusion and reaction phenomena using the generalized modified Poisson-Nernst-Planck (GMPNP) equations which include the effect of volume exclusion due to the solvated size of solution species. We demonstrate that the concentration of solvated cations builds at the outer Helmholtz plane (OHP) with increasing applied potential until the steric limit is reached. The formation of the EDL is expected to have important consequences for the transport of the CO2 molecule to the catalyst surface. The electric field in the EDL diminishes the pH in the first 5 nm from the OHP, with an accumulation of protons and a concomitant depletion of hydroxide ions. This is a considerable departure from the results obtained using reaction-diffusion models where migration is ignored. Finally, we use the GMPNP model to compare the nature of the EDL for different alkali metal cations to show the effect of solvated size and polarization of water on the resultant electric field. Our results establish the significance of the EDL and electrostatic forces in defining the local reaction environment of CO2 electrocatalysts. This journal is © The Royal Society of Chemistry.
英文关键词	Carbon dioxide; Electric fields; Electrocatalysts; Electrolytes; Electrolytic reduction; Positive ions; Alkali metal cations; Applied potentials; Electrical double layers; Electrocatalytic system; Poisson-nernst-planck; Reaction-diffusion models; Species concentration; Surface reaction energetics; Surface reactions; alkali metal; carbon dioxide; catalysis; catalyst; electric field; electrochemical method; electrolyte; ion; modeling; perforation; performance assessment; radiocarbon dating; reduction
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189788
作者单位	Materials for Energy Conversion and Storage (MECS), Department of Chemical Engineering, Delft University of Technology, Delft, HZ 2629, Netherlands; Department of Mathematics and Statistics, University of New Mexico, 310 SMLC, Albuquerque, NM 87131, United States; Inorganic Systems Engineering (ISE), Department of Chemical Engineering, Delft University of Technology, HZ Delft, 2629, Netherlands
推荐引用方式 GB/T 7714	Bohra D.,Chaudhry J.H.,Burdyny T.,et al. Modeling the electrical double layer to understand the reaction environment in a CO2 electrocatalytic system[J],2019,12(11).
APA	Bohra D.,Chaudhry J.H.,Burdyny T.,Pidko E.A.,&Smith W.A..(2019).Modeling the electrical double layer to understand the reaction environment in a CO2 electrocatalytic system.Energy & Environmental Science,12(11).
MLA	Bohra D.,et al."Modeling the electrical double layer to understand the reaction environment in a CO2 electrocatalytic system".Energy & Environmental Science 12.11(2019).