Efficient electroreduction of CO2 to syngas over ZIF-8 derived oxygen vacancy-rich ZnO nanomaterials. (21st February 2023)

• Record Type: Journal Article
• Authors: Yang, Jie; Wang, Hui; Yang, Han; Dong, Weiwei; Gao, Mingqi; Zhou, Guangying; Tian, Haiying; Zhang, Renjie; Wan, Jiqiang; Yang, Dexin
• Is Part Of: New journal of chemistry. Volume 47:Number 10(2023)
• Page Start: 4992
• Page End: 4998
• Publication Date: 2023-02-21
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d2nj05378k
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The oxygen vacancy-rich ZnO nanomaterials derived from ZIF-8 nanostructures exhibit good performance for CO2 electroreduction to syngas with the CO/H2 ratio changing from 1/3 to 8.5/1. Abstract : Electroreduction of CO2 is a sustainable approach to produce syngas with tunable CO/H2 ratios, which are required as specific reactants for the optimization of desired products. Herein, ZnO-d and ZnO-n nanomaterials were derived from zeolitic imidazolate framework-8 (ZIF-8) precursors with different morphologies, which exhibit good performance for CO2 electroreduction to syngas when using 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6, 30 wt%)/acetonitrile/water (H2 O, 5 wt%) as the supporting electrolyte. Regulation of the number of oxygen vacancies in different ZnO samples and the applied potentials during electrolysis can obviously affect the CO/H2 ratios in syngas, which would be changed from 1/3 to 8.5/1. Meanwhile, ZnO-n with abundant oxygen vacancies displays the highest CO faradaic efficiency (FE) of 73.2% with the total current density of 9.8 mA cm −2 at −1.9 V vs. Ag/Ag + . More oxygen vacancies and higher electrochemical specific surface area of ZnO-n can provide more active sites and facilitate the adsorption of CO2 and its intermediates. The smaller charge transfer impedance of ZnO-n can accelerate the electron and proton transfer, and thus improve the catalytic activity and the selectivity of products. In addition, the good synergistic effect between the [Bmim]PF6 -containing electrolyte and ZnO-n can enhance the formation of syngas.