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原子分散的s-块镁位用于CO2电还原制CO
作者:小柯机器人 发布时间:2021/9/25 18:58:55

中南大学刘敏团队报道了原子分散的s-块镁位用于CO2电还原制备CO。相关研究成果发表在2021年9月22日出版的国际学术期刊《德国应用化学》。

原子分散的过渡金属中心由于其强大的CO2活化能力,已被广泛研究用于CO2电还原反应(CO 2 RR)。然而,定向定域的d轨道和CO之间的强杂化极大地限制了CO的解吸,因此原子级的d轨道的活性是分散的过渡金属位。相比之下,s-块金属位具有非定向、非定域的3s轨道,因此CO吸附能力较弱,为解决CO解吸问题提供了一种很有前景的方法。

该文中,研究人员通过简单的CO2?RR热处理,在石墨氮化碳(Mg-C3N4)中构建了原子分散的镁原子。理论计算表明,CO在Mg位上的解吸比Fe位上更容易。该理论预测通过CO升温程序解吸实验和原位衰减全反射红外光谱得到证实。结果表明,在KHCO 3电解液中,高CO法拉第效率(≥90%)条件下,Mg-C3N4在H电池中的转换频率高达18000次/h,在流动电池中的电流密度高达300mA/cm2

该项工作为s-块金属位高效CO2RR转化为CO提供了新的思路。

附:英文原文

Title: Atomically Dispersed s-Block Magnesium Sites for Electroreduction of CO2 to CO

Author: Qiyou Wang, Kang Liu, Junwei Fu, Chao Cai, Huangjingwei Li, Yan Long, Shanyong Chen, Bao Liu, Hongmei Li, Wenzhang Li, Xiaoqing Qiu, Ning Zhang, Junhua Hu, Hao Pan, Min Liu

Issue&Volume: 2021-09-22

Abstract: Atomically dispersed transition metal sites have been extensively studied for CO  2  electroredution reaction (CO  2  RR) to CO due to their robust CO  2  activation ability. However, the strong hybridization between directionally localized d orbits and CO vastly limits CO desorption and thus the activities of atomically d ispersed transition metal sites. In contrast, s-block metal sites possess nondirectional ly delocalized 3s orbits and hence weak CO adsorption ability, providing a promising way to solve the suffered CO desorption issue. Herein , we constructed atomically dispersed magnesium atoms embedded in graphitic carbon nitride ( Mg-C  3  N  4  ) through a facile heat treatment for CO  2  RR . Theoretical calculations show that the CO desorption on Mg sites is easier than that on Fe and Co sites. This theoretical prediction is demonstrated by experimental CO temperature program desorption and  in-situ  attenuated total reflection infrared spectroscopy. As a result, Mg-C  3  N  4  exhibits a high turnover frequency of ~ 18,000 per hour in H-cell and a large current density of -300 mA/cm  2  in flow cell , under a high CO Faradaic efficiency ≥90% in KHCO  3  electrolyte . This work sheds a new light on s-block metal sites for efficient CO  2  RR to CO.

DOI: 10.1002/anie.202109329

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202109329

期刊信息

Angewandte Chemie:《德国应用化学》,创刊于1887年。隶属于德国化学会,最新IF:12.959
官方网址:https://onlinelibrary.wiley.com/journal/15213773
投稿链接:https://www.editorialmanager.com/anie/default.aspx