Qian Bai , Juanjuan Qi , Rongzhe Zhang , Zhiyuan Chen , Zihao Wei , Zhiyi Sun , Ziwei Deng , Xudong Yang , Qiangwei Li , Wenxing Chen , Lidong Wang
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引用次数: 0
Abstract
Asymmetric single-atom catalysts (ASACs) have attracted much attention owing to their excellent catalytic properties. However, the relationship between asymmetric coordination and the spin states of metal sites remains unclear. Additionally, the modulation of reactive oxygen species in Fenton-like reactions remains challenging. Herein, a novel strategy is reported for the rational design of highly loaded Co ASACs (CoN1C2/C2N) immobilized on three-dimensional flower-like C2N using an in situ-generated carbon defect method. In particular, the asymmetrically tricoordinated CoN1C2/C2N exhibited excellent catalytic activity for sulfachloropyridazine degradation, with a turnover frequency of 36.8 min–1. Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration (t2g6eg1) to the high-spin configuration (t2g5eg2) owing to asymmetric coordination. The high-spin Co 3d orbital in CoN1C2/C2N possessed more unpaired electrons and therefore, had a strong ability to gain electrons from the O 2p orbitals of HSO5–, boosting d-p orbital hybridization. More importantly, the spin-electron filling in the σ* orbital of high-spin Co 3d−O 2p accelerated the desorption of *SO5•−, which acted as a rate-limiting step in the reaction, thus facilitating more 1O2 generation. This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state, paving the way for advancements in environmental remediation and energy conversion applications.
期刊介绍:
The journal covers a broad scope, encompassing new trends in catalysis for applications in energy production, environmental protection, and the preparation of materials, petroleum chemicals, and fine chemicals. It explores the scientific foundation for preparing and activating catalysts of commercial interest, emphasizing representative models.The focus includes spectroscopic methods for structural characterization, especially in situ techniques, as well as new theoretical methods with practical impact in catalysis and catalytic reactions.The journal delves into the relationship between homogeneous and heterogeneous catalysis and includes theoretical studies on the structure and reactivity of catalysts.Additionally, contributions on photocatalysis, biocatalysis, surface science, and catalysis-related chemical kinetics are welcomed.