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Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

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Frontiers of Chemical Science and Engineering 2023年第12期17卷 1986-2000页

作者： Yi-Fan Xue Jie Feng Yun-Cai Song Wen-Ying Li State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China

Breakage of the C-N bond is a structure sensitive process,and the catalyst size significantly affects its *** the active metal nanoparticle scale,the role of catalyst size in C-N bond cleavage has not been clearly ***,Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature,and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C-N bond hybridization patterns as *** showed a 13 times higher reaction rate for sp3-hybridized C-N bond cleavage than sp2-hybridized C-N bond cleavage,while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size *** concentrations of terrace,step,and corner sites were found in different sizes of Ru *** relationship between catalytic site variation and C-N bond cleavage activity was further investigated by calculating the turnover frequency values for each *** analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C-N bond cleavage activity,and the step atoms are the active sites for the C-N bond *** Ru nanoparticles are smaller than 1.9 nm,they have a strong adsorption effect on the reactants,which will affect the catalytic performance of the Ru ***,these findings were also confirmed on other metallic Pd/Pt *** role of step sites in C-N bond cleavage was proposed using the density function theory *** reactants have stronger adsorption energies on the step atoms,and step atoms have d-band center nearer to the Fermi *** this case,the interaction with the reactant is stronger,which is beneficial for activating the C-N bond of the reactant.

关键词： sp3 sp2-hybridized C–N bond noble metal nanoparticle catalytic active site turnover frequency DFT

Surface Active Sites on Co_(3)O_(4) Nanobelt and Nanocube Model Catalysts for CO Oxidation

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Nano Research 2010年第5期3卷 363-368页

作者： Linhua Hu Keqiang Sun Qing Peng Boqing Xu Yadong Li Department of Chemistry Tsinghua UniversityBeijing 100084China

CO oxidation has been performed on Co_(3)O_(4) nanobelts and nanocubes as model *** Co_(3)O_(4) nanobelts which have a predominance of exposed{011}planes are more active than Co_(3)O_(4) nanocubes with exposed{001}*** programmed reduction of CO shows that Co_(3)O_(4) nanobelts have stronger reducing properties than Co_(3)O_(4) *** essence of shape and crystal plane effect is revealed by the fact that turnover frequency of Co3+sites of{011}planes on Co_(3)O_(4) nanobelts is far higher than that of{001}planes on Co_(3)O_(4) nanocubes.

关键词： CO oxidation Co_(3)O_(4) surface active sites turnover frequency model catalyst

N2O Decomposition Catalyzed by K＋-doped Bi0.02Co

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Chemical Research in Chinese Universities 2016年第3期32卷 418-422页

作者： TURSUN Mamutj an WANG Bingshuai JIANG Yan YU Haibiao SUN Xingtao WANG Xinping College of Chemistry & Environmental Science Kashgar University Kashgar 844000 P. R. China Liaoning Kelong Fine Chemical Co. Ltd. Liaoyang 111003 P. R. China Key Laboratory of Industrial Ecology and Environmental Engineering(MOE) and State Key Laboratory of Fine Chemical School of Environmental Science and Technology Dalian University of Technology Dalian 116024 P. R. China

K＋-doped Bi0.02Co was investigated as catalyst for N2O decomposition. It was found that the catalytic performance of the Bi0.02Co catalyst, which was prepared by coprecipitation method, can be effectively modified by potassium cations via impregnation. The optimized K0.01Bi0.02Co catalyst exhibited much higher activity compared with Bi0.02Co and K0.01Co for the reaction in feed gas 0.2% N2O/Ar, irrespective of the presence or absence of impurity gas（volume fraction） 5%02, 2%H20, 0.12%NO and 10%CO2. Characterization of the catalysts with H2 temperature programmed reduction（H2-TPR） and O2 temperature programmed desorption（O2-TPD） indicate that the Co--O bond in Bi0.02Co was weakened by the K＋ doping, and hence the K0.01Bi0.02Co catalyst has much higher turnover frequency（TOF） than CO3O4 spinel and Bi0.02Co for the reaction.

关键词： N2O turnover frequency Reaction order H2 temperature programmed reduction O2 temperature programmed desorption

In situ evolution of surface Co_(2)CrO_(4) to CoOOH/CrOOH by electrochemical method:Toward boosting electrocatalytic water oxidation

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Chinese Journal of Catalysis 2021年第7期42卷 1096-1101页

作者： Jinxiu Zhao Xiang Ren Xu Sun Yong Zhang Qin Wei Xuejing Liu Dan Wu Collaborative Innovation Centre for Green Chemical Manufacturing and Accurate Detection School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022ShandongChina Key Laboratory of Interfacial Reaction&Sensing Analysis in Universities of Shandong School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022ShandongChina

Developing non‐noble‐metal electrocatalyst with efficient and durable activity is a urgent task for addressing the sluggish reaction kinetics of electrochemical water *** evolution of the electrocatalyst is an important strategy for achieving enhanced ***,in situ evolution of surface Co_(2)CrO_(4) to CoOOH/CrOOH(CoOOH/CrOOH‐Co_(2)CrO_(4))by an electrochemical method under alkaline conditions was designed for enhancing the electrocatalytic performance of water *** experiments demonstrated that the synergy between CoOOH/CrOOH and Co_(2)CrO_(4) resulted in a marked increase in the number of active sites and improved the rate of charge transfer,which enhanced the activity for water *** a geometrical current density of 20 mA cm^(−2),the overpotential of the oxygen evolution reaction was 244 mV and the turnover frequency was 0.536 s^(−1) in 1.0 M NaOH.

关键词： CoOOH/CrOOH‐Co_(2)CrO_(4)nanosheet Anodizing evolution Electrochemical catalysis Oxygen evolution reaction turnover frequency

Carbon monoxide powered fuel cell towards H_(2)-onboard purification

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Science Bulletin 2021年第13期66卷 1305-1311,M0004页

作者： Yang Li Xian Wang Bingbao Mei Ying Wang Zhaoyan Luo Ergui Luo Xiaolong Yang Zhaoping Shi Liang Liang Zhao Jin Zhijian Wu Zheng Jiang Changpeng Liu Wei Xing Junjie Ge State Key Laboratory of Electroanalytic Chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201204China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Shanghai Synchrotron Radiation Facility Zhangjiang National LaboratoryShanghai Advanced Research InstituteChinese Academy of ScienceShanghai 201204China University of Chinese Academy of Sciences Beijing 100049China

Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(<10 ppm),owning to the preferential CO adsorption and the consequential blockage of the catalyst ***,however,we report that CO i... 详细信息

Proton exchange membrane fuel cells(PEMFCs)suffer extreme CO poisoning even at PPM level(turnover frequency(64.65 s^(-1),363 K)far exceeding any chemical or electrochemical catalysts ***,this feature enables efficient CO selective removal from H_(2) gas stream through the PEMFC technique,with CO concentration reduced by one order of magnitude through running only one single cell,while simultaneously harvesting *** attribute such catalytic behavior to the weak CO adsorption and the co-activation of H_(2)O due to the interplay between two adjacent Rh sites.

关键词： CO electrooxidation Hydrogen purification Proton exchange membrane fuel cells turnover frequency Rh based single atom catalyst

CO and C3Hs Total Oxidation over Pd Catalysts Supported on Commercial Ce-Zr Solid Solution： Effects of the Calcination Temperature and Hydrothermal Treatment

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Chemical Research in Chinese Universities 2015年第2期31卷 288-293页

作者： ZHOU Renmei ZHANG Xuanyu LU Jiqing HU Gengshen LUO Mengfei Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 P. R. China

A series of Pd catalysts supported on commercial Ce-Zr solid solution（Pd/CZ） calcined at different tem- peratures（750, 900 and 1050 %℃） was prepared via an incipient wetness impregnation method. The activities of the fresh and hydrothermally aged PdTCZ catalysts were tested for total oxidation of CO and C3H8. For CO oxidation, the activity of either fresh or aged Pd/CZ catalysts decreased with the elevating of calcination temperature of CZ support, with a fresh catalyst calcined at 750 ℃ possessing the highest activity and hydrothermal stability. For C3H8 total oxidation, the activity of Pd/CZ catalysts could be improved by increasing the calcination temperature of support. However, the aged Pd/CZ catalysts showed higher activity than corresponding fresh Pd/CZ catalysts. The turnover frequency（TOF） over Pd/CZ catalyst for CO oxidation increased with increasing reduction ability of the catalysts, with a fresh catalyst calcined at 750 ℃ having the highest value（0.27 s^-1）. However, the TOF of Pd/CZ catalyst for C3Hs total oxidation was mainly affected by the size of Pd particles, and large Pd particles possessed a higher activity, with the highest TOF value（0.96s^-1） obtained over an aged catalyst calcined at 1050 ℃.

关键词： Pd/Ce-Zr catalyst Stability turnover frequency Hydrothermal aging

Improved Catalytic Reaction of Biotemplated Palladium Nanoparticles through Immobilized Metal Affinity Purification

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Advances in Nanoparticles 2023年第1期12卷 22-31页

作者： Shadrach Ibinola Hazim Aljewari Imann Mosleh Robert Beitle Ralph E. Martin Department of Chemical Engineering University of Arkansas Fayetteville USA

To investigate the effect purification plays on nanoparticle (NP) synthesis and catalytic activity, three copies of Pd4 (TSNAVHPTLRHL) fused to the N-terminus of Green Fluorescent Protein (GFP) was produced recombinantly and its characteristics pre and post purification was assessed. An E. coli expression system was employed, and purification was performed with Immobilized Metal Affinity Column (IMAC). Transmission electron microscopy (TEM) was utilized to examine the morphology of NPs synthesized with an enriched protein sample and ImageJ was used to determine the average size to be 2.44 nm. The turnover frequency of fabricated NP from the purified protein was analyzed by a model Suzuki-Miyaura coupling reactions and determined to be 33,000 hr-1. This value is three times higher than the turnover frequency when crude lysate containing (Pd4)3-GFP was used during NP synthesis. This result shows that enrichment enhanced the catalytic activity of NP.

关键词： Protein Expression Nanoparticle Synthesis turnover frequency Suzuki-Miyaura