氢氧化钴的化学和电化学合成：选择性相变及其在不同电催化反应中的应用,Journal of Materials Chemistry A

当前位置： X-MOL 学术 › J. Mater. Chem. A › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

氢氧化钴的化学和电化学合成：选择性相变及其在不同电催化反应中的应用
Journal of Materials Chemistry A ( IF 10.7 ) Pub Date : 2022-05-06 , DOI: 10.1039/d2ta02166h
Joon Yong Park ₁ , Ha Young Kim ₁ , Yong-Il Kim ₂ , So Yeong Jo ₁ , Syed Asad Abbas ₁ , Dongho Seo ₁ , Ahyeon Ma ₁ , Ki Min Nam ₁

Affiliation

具有明确识别晶体结构的单个氢氧化钴有助于辨别晶体结构和催化活性之间的关系。_{在此，全面研究了 α-Co(OH) 2}的晶体结构及其向其他氢氧化钴的转变。α-Co(OH) ₂结构由带有阴离子插层的层状结构组成，[Co ^Oh_0.77 Co ^Td_0.23 (OH) _1.77 ] ^0.23+ [Cl _0.23 ·0.64H ₂ O]，通过使用 X 的 Rietveld 精修分析确定-射线衍射。亚稳态α-Co(OH) _2的相变通过化学环境的变化选择性地转化为各种其他氢氧化钴，如β-Co(OH) ₂、γ-CoOOH和β-CoOOH，并充分表征了它们的结构。此外，α-Co(OH) ₂和 β-Co(OH) _{2的电化学氧化转化}分别成功地实现了γ-CoOOH和β-CoOOH的转化。将制备的氢氧化钴应用于析氧反应 (OER) 和氯化物氧化反应 (COR) 以研究晶体结构与活性之间的相关性。γ-CoOOH表现出比β-CoOOH更好的OER催化活性。相比之下，β-CoOOH 表现出比 γ-CoOOH 更高的 COR 选择性。有趣的是，在浓度为 0.1 M NaCl 的 β-CoOOH 上，COR 的法拉第效率超过 97%，与所有其他电极相比，该值是最高的 COR 法拉第效率。阐明了晶体结构对每个电催化反应的重要性。

"点击查看英文标题和摘要"

Chemical and electrochemical synthesis of cobalt hydroxides: selective phase transformation and application to distinct electrocatalytic reactions

Individual cobalt hydroxides with clearly identified crystal structures can aid in discerning the relationship between the crystal structure and catalytic activity. Herein, the crystal structure of α-Co(OH)₂ and its transformations to other cobalt hydroxides are fully investigated. The α-Co(OH)₂ structure comprised a layered structure with anion intercalation, [Co^Oh_0.77Co^Td_0.23(OH)_1.77]^0.23+[Cl_0.23·0.64H₂O], which was identified by Rietveld refinement analysis using X-ray diffraction. Phase transformations of metastable α-Co(OH)₂ into various other cobalt hydroxides, such as β-Co(OH)₂, γ-CoOOH, and β-CoOOH, were selectively performed through a variation in the chemical environment, and their structures were fully characterized. In addition, electrochemical oxidative transformations of α-Co(OH)₂ and β-Co(OH)₂ into γ-CoOOH and β-CoOOH, respectively, were successfully accomplished. The prepared cobalt hydroxides were applied to the oxygen evolution reaction (OER) and chloride oxidation reaction (COR) to investigate the correlation between the crystal structure and activity. The γ-CoOOH showed better OER catalytic activity than β-CoOOH. In contrast, β-CoOOH showed higher COR selectivity than γ-CoOOH. Interestingly, the faradaic efficiency of the COR was over 97% on β-CoOOH at a concentration of 0.1 M NaCl, and this value is the highest COR faradaic efficiency compared to all other electrodes. The importance of the crystal structure for each electrocatalytic reaction is elucidated.

更新日期：2022-05-06

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南