Atomic-level Engineered Cobalt Catalysts for Fenton-Like Reactions: Synergy of Single Atom Metal Sites and Nonmetal-bonded Functionalities

Adv Mater. 2024 Apr 29:e2401454. doi: 10.1002/adma.202401454. Online ahead of print.

Abstract

Single atom catalysts (SACs) are atomic-level-engineered materials with high intrinsic activity. Catalytic centers of SACs are typically the transition metal (TM)-nonmetal coordination sites, while the functions of co-existing non-TM-bonded functionalities are usually overlooked in catalysis. Herein, we reported the scalable preparation of carbon-supported cobalt-anchored SACs (CoCN) with controlled Co-N sites and free functional N species. We first systematically study the role of metal and nonmetal bonded functionalities in the SACs for peroxymonosulfate (PMS)-driven Fenton-like reactions, revealing their contribution to performance improvement and pathway steering. Experiments and computations demonstrate that the Co-N3C coordination plays a vital role in the formation of a surface-confined PMS* complex to trigger the electron transfer pathway and promote kinetics because of the optimized electronic state of Co centers, while the non-metal-coordinated graphitic N sites act as preferable pollutant adsorption sites and additional PMS activation sites to accelerate electron transfer. Synergistically, CoCN exhibits ultrahigh activity in PMS activation for p-hydroxybenzoic acid oxidation, achieving complete degradation within 10 min with an ultrahigh turnover frequency of 0.38 min-1, surpassing most reported materials. These findings offer new insights into the versatile functions of N species in SACs and inspire rational design of high-performance catalysts in complicated heterogeneous systems. This article is protected by copyright. All rights reserved.

Keywords: Fenton‐like reactions; electron transfer pathway; nitrogen species; peroxymonosulfate; single‐atom catalysts.