中国科学院重庆绿色智能技术研究院机构知识库

QQ客服 官方微博 反馈留言

	A novel electrochemical method determining pKa and transport parameters of buffers using acid-base transport limitation response
	Yin, Fengjun1,2; Hu, Yutong1,2; Lu, Shun1; Yang, Xiaohui1; Song, Cheng1; Liu, Hong1,2
	2023-12-10
摘要	Dissociation constant (logarithmic form, pKa) and diffusion coefficient (D) are two fundamental physical parameters for weak acids and bases (buffers). Their effortless determinations from one method are not available yet. Herein, we propose an innovative method to determine pKa and D values based on a brand-new principle of electrochemical acid-base transport limitation (eABTL). The significance of eABTL lies in its ability to relate inert buffers to electrode reactions, enabling the acquisition of electrochemical responses for inert species. Acid-base transport limiting current (jl) is the only variable that needs to be measured. The pKa and transport coefficient (m) are determined from the relationship of jl vs. solution pH and jl vs. buffer concentration, respectively. Three ways are available for D determinations by introducing the expressions of diffusion layer thickness. The method is demonstrated using rotating disc electrodes to implement hydrogen evolution reaction. The pKa, m and D values exhibit good repeatability in multiple determinations. A well-defined electrode geometry is necessary for accurate D determination. This method can be developed to a family of methods with the advantages for fast estimating practical parameter values of buffers.
关键词	Electrochemical acid-base transport limitation Buffer Dissociation constant Diffusion coefficient Hydrogen evolution reaction
DOI	10.1016/j.electacta.2023.143373
发表期刊	ELECTROCHIMICA ACTA
ISSN	0013-4686
卷号	471页码:9
通讯作者	Liu, Hong(liuhong@cigit.ac.cn)
收录类别	SCI
WOS记录号	WOS:001107011200001
语种	英语