单原子活化过一硫酸盐性能更好?与金属氧化物耦合可能更高效  

Is single-atom catalyzed peroxymonosulfate activation better?Coupling with metal oxide may be better

作　　者：张俊磊 刘文聪 刘彪 段晓光 敖志敏 朱明山 Junlei Zhang;Wencong Liu;Biao Liu;Xiaoguang Duan;Zhimin Ao;Mingshan Zhu(Guangdong Key Laboratory of Environmental Pollution and Health,School of Environment,Jinan University,Guangzhou 511443,Guangdong,China;Advanced Interdisciplinary Institute of Environment and Ecology,Beijing Normal University,Zhuhai 519087,Guangdong,China;School of Chemical Engineering,The University of Adelaide,Adelaide,SA 5005,Australia;School of Materials Science and Engineering,State Key Laboratory of Solidification Processing,Atomic Control&Catalysis Engineering Laboratory,Northwestern Polytechnical University,Xi’an 710072,Shaanxi,China)

机构地区：[1]暨南大学环境学院,广东省环境污染与健康重点实验室,广东广州511443 [2]北京师范大学环境与生态前沿交叉研究院,广东珠海519087 [3]阿德莱德大学化工学院,澳大利亚阿德莱德 [4]西北工业大学材料科学与工程学院,凝固技术国家重点实验室,陕西西安710072

出　　处：《Chinese Journal of Catalysis》2024年第4期137-148,共12页催化学报（英文）

基　　金：国家自然科学基金(52300218);国家自然科学基金(22322604);国家自然科学基金(22176041);广东省珠江人才引进计划(2019QN01L148)。

摘　　要：单原子催化剂(SAC)作为新一代过一硫酸盐(PMS)非均相活化剂,具有原子利用率高、结构稳定性强等优点,为新兴有机污染物(EOPs)的高效降解提供了新的解决方案.然而,SAC的活性位点密度依然受限于严苛的制备工艺等,而这严重影响PMS的进一步激活.因此,发展SAC基PMS高级氧化技术的关键之一在于提升SAC的活性位点密度,进而增强PMS活化效率.相比之下,传统的过渡金属氧化物(MOx)作为PMS活化剂,尽管存在金属原子利用率低和金属离子易溶出等问题,但其表面具有丰富的金属活性位点.统筹SAC与MOx的优缺点,本文提出了一种“新-老”结合策略,即将传统MOx与新一代SAC耦合,发展兼具丰富金属活性位点和优良结构稳定性的PMS活化剂,实现PMS的高效活化.本文采用预配位-重结晶-热解路径,结合金属离子源投加量控制,制备了具有金属氧化物与单原子组分的Co_(3)O_(4)@Co1/C_(3)N_(5)复合PMS非均相活化剂,并系统研究了其活化PMS降解EOPs的性能.粉末X射线衍射、X射线光电子能谱、高角环形暗场扫描透射电子显微镜及X射线吸收谱结果表明,Co_(3)O_(4)@Co1/C_(3)N_(5)由金属氧化物Co_(3)O_(4)和单原子Co1/C_(3)N_(5)组成,并且Co_(3)O_(4)纳米晶体被锚定在Co1/C_(3)N_(5)纳米片表面.在降解典型EOPs双氯芬酸钠(DCF)的过程中,Co_(3)O_(4)@Co1/C_(3)N_(5)活化的PMS体系展现了显著增强的性能.相比基于Co_(3)O_(4)和Co1/C_(3)N_(5)活化的PMS体系,DCF的降解速率分别提高了约28.0倍和2.5倍,证明Co_(3)O_(4)@Co1/C_(3)N_(5)具有显著增强的PMS活化能力.这主要因为Co1/C_(3)N_(5)和Co_(3)O_(4)之间形成的Co1-O(Co_(3)O_(4))和Co-N(Co1/C_(3)N_(5))化学键有效地促进了电荷迁移.结合密度泛函理论计算发现,Co1/C_(3)N_(5)和Co_(3)O_(4)之间的强电子相互作用显著强化了PMS的吸附,降低了PMS分解生成活性物质的能垒.此外,Co_(3)O_(4)@Co1/C_(3)N_(5)具有良好的复杂环境因素(包括pH、�Single-atom catalysts(SACs)as a new class of peroxymonosulfate(PMS)activator are still limited by the low metal loading and activity.Here,we introduce a new strategy of interfacial coupling SACs with metal oxides to fine-tune the active single-atom sites and improve the atomic utilization efficiency.Taking Co_(3)O_(4)@Co1/C_(3)N_(5) as a case,the formation of heterostructures enhanced the activity of outer-sphere SACs for PMS activation,further upgrading the kinetics of diclofenac sodium degradation.The degradation rate of the composite increases by up to approximately 28.0 and 2.5 times compared to Co_(3)O_(4)and Co1/C_(3)N_(5),respectively.The Co1-O(Co_(3)O_(4))and Co-N(Co1/C_(3)N_(5))bonds between Co1/C_(3)N_(5) and Co_(3)O_(4) make a tightly coupled interface for charge migration,which synergically optimizes the PMS adsorption configuration toward reactive species generation with lower activation energy.Co_(3)O_(4)@Co1/C_(3)N_(5) also exhibits excellent reusability and can be employed in broad application scenarios.

关 键 词：单原子催化剂 金属氧化物 协同效应 过一硫酸盐活化 Co_(3)O_(4)@Co1/C_(3)N_(5) 

分 类 号：TQ426[化学工程]