高暴露Co-N-C单原子催化剂设计及其在氧还原反应中的应用
De novo-design of highly exposed Co-N-C single-atom catalyst for oxygen reduction reaction
周丹 1朱宏跃 1赵阳 2刘一鸣1
作者信息
- 1. 太原科技大学催化转化能源耦合山西省重点实验室,山西太原 030024
- 2. 中国科学院大连化学物理研究所洁净能源国家重点实验室,辽宁大连 116023
- 折叠
摘要
高载量氮配位金属M-N-C单原子催化剂(SAC)一般通过一锅法直接高温热解合成,然而高碳化温度(>700℃)易导致碳骨架畸变、孔道塌缩,使大部分金属单原子被包埋在碳基质中而无法在催化过程中被利用.本研究基于硬软酸碱(HSAB)理论发展了一种简便的合成方法,利用具有充分暴露吡啶-N外部位点的氮掺杂的碳载体,在 60℃下通过硬软酸碱的直接配位制备出具有高暴露度的金属原子与吡啶-N位点配位的Co单原子催化剂.得益于高度可及的Co活性位点,所制备的Co-N-C SAC展现出与商业Pt/C催化剂相媲美的氧还原活性,并且在 0.85 V(相对于可逆氢电极)时获得了高达 0.93 e-1·s-1·site-1 的周转频率(TOF),明显超过一些文献中已报道的具有超高金属含量的代表性单原子催化剂.本工作为设计和制备具有高可及性、高密集性单原子位点的M-N-C单原子催化剂提供了一种可行的合成策略.
Abstract
The nitrogen-coordinated metal single-atom catalysts(M-N-C SACs)with an ultra-high metal loading synthetized by direct high-temperature pyrolysis have been widely reported.However,most of metal single atoms in these catalysts were buried in the carbon matrix,resulting in a low metal utilization and inaccessibility for adsorption of reactants during the catalytic process.Herein,we reported a facile synthesis based on the hard-soft acid-base(HSAB)theory to fabricate Co single-atom catalysts with highly exposed metal atoms ligated to the external pyridinic-N sites of a nitrogen-doped carbon support.Benefiting from the highly accessible Co active sites,the prepared Co-N-C SAC exhibited a superior oxygen reduction reactivity comparable to that of the commercial Pt/C catalyst,showing a high turnover frequency(TOF)of 0.93 e-·s-1·site-1 at 0.85 V vs.RHE,far exceeding those of some representative SACs with a ultra-high metal content.This work provides a rational strategy to design and prepare M-N-C single-atom catalysts featured with high site-accessibility and site-density.
关键词
硬软酸碱/Co-N-C/单原子催化剂/高可及度活性位/氧还原反应Key words
hard-soft acid-base/Co-N-C/single-atom catalyst/highly accessible active sites/oxygen reduction reaction引用本文复制引用
出版年
2025
国家科技期刊平台
NSTL
万方数据