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Engineering a Local Free Water Enriched Microenvironment for Surpassing Platinum Hydrogen Evolution Activity
2022-06-25 13:39

华中科技大学翟天佑团队提出了构建局部游离水富集微环境超越铂析氢活性。相关研究成果发表在2022年6月22日出版的国际学术期刊《德国应用化学》。

操纵催化剂-电解质界面将反应物推入内亥姆霍兹平面(IHP)是高效电催化剂的理想选择,然而,由于电化学IHP和惰性催化剂表面很少实现。

该文中,研究人员提出通过表面羟基引入局部力场来设计电化学微环境并增强碱性析氢活性。以羟基固定化Ni/Ni3C异质结构为原型,研究人员发现表面羟基诱导的局部氢键将4-配位氢键合H2O分子穿过IHP变为游离H2O,从而持续为催化位点提供反应物。此外,羟基与Ni/Ni3C异质结构的耦合通过极化效应进一步降低了水的离解能。作为直接结果,富羟基催化剂在碱性介质中的高电流密度(500 mA cm-2@~276 mV)下超过Pt/C活性。

附:英文原文

Title: Engineering a Local Free Water Enriched Microenvironment for Surpassing Platinum Hydrogen Evolution Activity

Author: Qunlei Wen, Junyuan Duan, Wenbin Wang, Danji Huang, Youwen Liu, Yongliang Shi, Jiakun Fang, Anmin Nie, Huiqiao Li, Tianyou Zhai

Issue&Volume: 2022-06-22

Abstract: Manipulating the catalyst-electrolyte interface to push reactants into inner Helmholtz plane (IHP) is desirable for efficient electrocatalysts, however, has rarely been implemented due to the elusive electrochemical IHP and inert catalyst surface. Here, we propose the introduction of local force fields by surface hydroxyl group to engineer the electrochemical microenvironment and enhance alkaline hydrogen evolution activity. Taking hydroxyl group immobilized Ni/Ni  3  C heterostructure as a prototype, we revealed that the local hydrogen bond induced by the surface hydroxyl group drag 4-coordinated hydrogen-bonded H  2  O molecules across the IHP to become free H  2  O and thus continuously supply reactants for catalytic sites. In addition, the hydroxyl group coupled with Ni/Ni  3  C heterostructure further lowers the water dissociation energy by polarization effect. As a direct outcome, hydroxyl-rich catalysts surpass Pt/C activity at high current density (500 mA cm  -2  @ ~276 mV) in alkaline medium.

DOI: 10.1002/anie.202206077

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202206077

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