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Shedding light on the reversible deactivation of carbon-supported single-atom catalysts in hydrogenation reaction

Nano Research 2024年第6期17卷 4807-4814页

作者： Runze Chen Xiaoying Wang Jianfei Dang Songjie Yun Liqiang Wang Fangong Kong You-Nian Liu State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyJinan 250353China School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China Hunan Provincial Key Laboratory of Micro&Nano Materials Interface Science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China

Carbon-supported single-atom catalysts were found to suffer reversible deactivation in catalytic hydrogenation,but the mechanism is still ***,nitro compounds hydrogenation catalyzed by N-doped carbon-supported Co single atom(Co1/NC)was taken as a model to uncover the mechanism of the reversible deactivation ***1/NC exhibited moderate adsorption towards the substrate molecules(i.e.,nitro compounds or related intermediates),which could be strengthened by the confinement effect from the porous ***,substrate molecules tend to accumulate within the pore channel,especially micropores that host Co1,making it difficult for the reactants to access the active sites and finally leading to their *** situation could be even worse when the substrate molecules possess a large ***,the catalytic activity of Co1/NC could be restored via a simple thermal treatment,which could remove the adsorbates within the pore channel,hence releasing active sites that were originally inaccessible to reactants.

关键词： single-atom catalysts porous carbon support reversible deactivation mechanistic study hydrogenation reaction

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Probing reaction pathways for H_(2)O-mediated HCHO photooxidation at room temperature

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Nano Research 2021年第5期14卷 1471-1478页

作者： Weiwei Shao Xiaodong Li Xiaolong Zu Liang Liang Yang Pan Junfa Zhu Chengming Wang Yongfu Sun Yi Xie Hefei National Laboratory for Physical Sciences at Microscale National Synchrotron Radiation LaboratoryHefei Science Center of CASUniversity of Science and Technology of ChinaHefei230026China Institute of Energy Hefei Comprehensive National Science CenterHefei230031China

Photooxidation provides a promising strategy for removing the dominant indoor pollutant of HCHO,while the underlying photooxidation mechanism is still unclear,especially the exact role of H2O ***,we utilize in-situ spectral techniques to unveil the H2O-mediated HCHO photooxidation *** an example,the synthetic defective Bi2WO6 ultrathin sheets realize high-rate HCHO photooxidation with the assistance of H2O at room ***-situ electron paramagnetic resonance spectroscopy demonstrates the existence of•OH radicals,possibly stemmed from H2O oxidation by the photoexcited ***-radiation vacuum ultraviolet photoionization mass spectroscopy and H218O isotope-labeling experiment directly evidence the formed•OH radicals as the source of oxygen atoms,trigger HCHO photooxidation to produce CO2,while in-situ Fourier transform infrared spectroscopy discloses the HCOO*radical is the main photooxidation ***-functional-theory calculations further reveal the•OH formation process is the rate-limiting step,strongly verifying the critical role of H2O in promoting HCHO *** work first clearly uncovers the H2O-mediated HCHO photooxidation mechanism,holding promise for high-efficiency indoor HCHO removal at ambient conditions.

关键词： mechanistic study H_(2)O-mediated HCHO photooxidation room temperature

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mechanistic Studies on Propargyl Alcohol-Tethered Alkylidenecyclopropane with Aryldiazonium Salt Initiated by Visible Light

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Chinese Journal of Chemistry 2021年第2期39卷 295-300页

作者： Jiaxin Liu Yin Wei Min Shi State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisUniversity of Chinese Academy of ScienceShanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling RoadShanghai200032 China Shenzhen Grubbs Institute Southern University of Science and TechnologyShenzhenGuangdong518000 China

This paper discloses the reaction mechanism of two consecutive but different visible light photo-induced chain processes for the rapid construction of spirobi[indene]*** first process is triggered by a photo-induced single-electron-transfer(SET)of an electron donor-accepter(EDA)*** second process is initiated by a direct SET process between aryldiazonium salt and the excited allenic *** these two processes,another SET took place respectively on the in situ formed radical intermediate to realize a redox-neutral *** mechanistic studies have been carried out by control experiments,kinetic and spectroscopic analyses,deuterium labeling experiments to support these two chain processes.

关键词： mechanistic study Photochemistry Radical ion Spirobi[indene] Radical chain

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Synergistic degradation of phenols by bimetallic CuO-Co_3O_4@γ-Al_2O_3 catalyst in H_2O_2/HCO_3^- system

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Chinese Journal of Catalysis 2016年第6期37卷 963-970页

作者：李一冰 Ali Jawad Aimal Khan 卢小艳陈朱琦刘卫东尹国川浙江师范大学化学与生命科学学院浙江金华321004 华中科技大学化学与化工学院湖北武汉430074

The development of new catalytic techniques for wastewater treatment has long attracted much attention from industrial and academic ***,because of catalyst leaching during degradation,catalysts can be short lived,and therefore expensive,and unsuitable for use in wastewater *** this work,we developed a bimetallic CuO-Co3O4@γ-Al2O3 catalyst for phenol degradation with bicarbonate-activated *** weakly basic environment provided by the bicarbonate buffer greatly suppresses leaching of active Cu and Co metal ions from the catalyst.X-ray diffraction and X-ray photoelectron spectroscopy results showed interactions between Cu and Co ions in the CuO-Co3O4@γ-Al2O3 catalyst,and these improve the catalytic activity in phenol *** studies using different radical scavengers showed that superoxide and hydroxyl radicals both played significant roles in phenol degradation,whereas singlet oxygen was less important.

关键词： Synergistic effect Phenol degradation Copper/cobalt oxide catalyst mechanistic study Bicarbonate-activated H2O2

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ME-PPD, derivative of PPD, significantly attenuating the skin sensitizing response by studies anchored to the skin sensitization AOP and clinical cross-reaction studies

ME-PPD, derivative of PPD, significantly attenuating the ski...

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中国毒理学会第九次全国毒理学大会

作者： Wenbo Xin Thomas Koch Carsten Goebel Global Product Stewardship Coty

The strong sensitizing potencies of the most important precursors of oxidative hair dyes,p-phenylenediamine（PPD） and p-toluylenediamine（PTD, i.e. 2-methyl-PPD） are well established,which are considered as the key sensitizers in hair dye allergic contact *** the rate of positive PPD patch test results in a large series of dermatitis patients is approximately 6.2% in North America and 4% in both Europe and ***, with the introduction of a methoxymethyl side chain into PPD, 2-methoxymethyl-pphenylenediamine（ME-PPD） was found to deliver excellent hair coloring performance while significantly reducingthe sensitizing potential compared to PPD and PTD. In in vitro studies, ME-PPD showed an attenuated innate immune response when analyzed for its protein reactivity and dendritic cell activation potential. In vivo, the effective concentration of ME-PPD necessary to induce an immune response 3-fold above vehicle control（EC3 value） in the local lymph node assay（LLNA） was 4.3%, indicating a moderate skin sensitizing potency compared to values of 0.1 and 0.17% for PPD and PTD, respectively. In addition, the skin sensitizing induction risk of ME-PPD under consumer hair dye usage conditions was assessed through a quantitative risk assessment（QRA） indicatingthat the risk was negligible compared to PPD or *** there is a substantial rate of cross-elicitation of allergic contact dermatitis to other important hair dye molecules（such asPTD） in PPD-allergic patients, the tolerance to ME-PPD was also studied in three patient populations in the USA and in *** 73 PPD-allergic patients were exposed to a hair dye product containing 2% ME-PPD instead of2% PPD for 30 or 45 min on their forearm（simulating hair dye use conditions） no elicitation response was observed in 45（62%）. Among the 28 PPD allergic patients that reacted to both ME-PPD and PPD under these conditions, 24（85%） showed a reduced reaction strength in response to ME-PPD. Hence based on the above s

关键词： hair dye PPD 2-methoxymethyl-p-phenylenediamine(ME-PPD) alternative methods mechanistic study QRA cross-reaction

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苯乙烯-乙烯-1-丁烯共聚物功能化反应的选择性机制研究

苯乙烯-乙烯-1-丁烯共聚物功能化反应的选择性机制研究

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2012年全国高分子材料科学与工程研讨会

作者：于海珠苏圣钦党智敏胡国华北京科技大学高分子科学与工程系

＜正＞运用自由基反应对高分子聚合物进行功能化是制备功能高分子的重要手段,其中多组分共聚物上的高选择性/可控功能化过程是实现这一目标的有效途径。最近,意大利的Ciardelli教授课题小组报道了过氧化二异丙苯（DCP）引发的马来酸二... 详细信息

＜正＞运用自由基反应对高分子聚合物进行功能化是制备功能高分子的重要手段,其中多组分共聚物上的高选择性/可控功能化过程是实现这一目标的有效途径。最近,意大利的Ciardelli教授课题小组报道了过氧化二异丙苯（DCP）引发的马来酸二乙酯（DEM）对苯乙烯-乙烯-1-丁烯的三嵌段共聚物（SEBS）的功能化反应。实验发现通过调控DEM与DCP的配比,可以使功能化过程主要发生在聚合物的烷基碳原子上。

关键词： Controlled ftinctionalization SEBS mechanistic study

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