Mining, Minerals Processing and Metallurgical Engineering

Electrochemical mechanism and kinetics of electrodissolution-coupled hafnium alkoxide synthesis in tetraethylammonium-chloride-based anhydrous system

  • 李 帅,杨声海,陈永明,唐朝波,赖延清,邓朝勇,王长红
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  • 1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
    2. Ximei Resources Limited Company, Qingyuan 513000, China

Online published: 2025-11-04

Abstract

Electrodissolution-coupled hafnium alkoxide synthesis (EHS) is a promising pathway for efficient electro- synthesis. It employs simultaneous heterogeneous reactions of Hf dissolution and ethanol dehydrogenation, and spontaneous solution-based combination reaction between Hf4+ cations and alkoxy anions. To elucidate the mechanism and kinetics of EHS process, the electrochemical behaviors of anodic Hf dissolution and cathodic ethanol dehydrogenation were explored through electrochemical measurements, SEM observations, gas chromatography, and micro-kinetics modeling. The results indicated the supporting electrolytes of tetraethylammonium chloride (Et4NCl) to be preferable, which facilitated a passive-film-punctured pitting mechanism for Hf dissolution and a two-stage dehydrogenation mechanism. Three indicators related to passive rate, sensitivity towards puncture of the passive film, and pitting rate were extracted to quantify the kinetics of passive puncture and Hf corrosion. Micro-kinetics models were developed to evaluate the Et4NCl-based EHS process, which achieved electric energy requirements of 1.53-1.83 kW·h/kg Hf(OC2H5)4.

Cite this article

李 帅,杨声海,陈永明,唐朝波,赖延清,邓朝勇,王长红 . Electrochemical mechanism and kinetics of electrodissolution-coupled hafnium alkoxide synthesis in tetraethylammonium-chloride-based anhydrous system[J]. Transactions of Nonferrous Metals Society of China, 2024 , 34(5) : 1681 -1693 . DOI: 10.1016/S1003-6326(24)66499-X

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