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Interfacial oxidized Pd species dominate catalytic hydrogenation of polar unsaturated bonds

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Nano Research 2024年第1期17卷 228-234页

作者： Pengyao You Shaoqi Zhan Pengpeng Ruan ruixuan qin Shiguang Mo Yazhou Zhang Kunlong Liu Lansun Zheng Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materialsand Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Department of Chemistry BMCUppsala UniversityBMC Box 576Uppsala S-75123Sweden Department of Chemistry University of OxfordOxford OX13QZUK

The determination of catalytically active sites is crucial for the design of efficient and stable catalysts toward desired ***,the complexity of supported noble metal catalysts has led to controversy over the locations of catalytically active sites(e.g.,metal,support,and metal/support interface).Here we develop a structurally controllable catalyst system(Pd/SBA-15)to reveal the catalytic active sites for the selective hydrogenation of ketones to alcohol using acetophenone hydrogenation as model *** investigations demonstrated that unsupported Pd nanocrystals have no catalytic activity for acetophenone ***,oxidized Pd species were catalytically highly active for acetophenone *** catalytic activity decreased with the decreased oxidation state of *** work provides insights into the hydrogenation mechanism of ketones but also other unsaturated compounds containing polar bonds,e.g.,nitrobenzene,N-benzylidene-benzylamine,and carbon dioxide.

关键词： oxidized Pd metal/oxide interface constant particle size Pd/SBA-15 acetophenone hydrogenation

Surface Ligand Evolution:Sulfur-Directed Covalent Bonding of PPh_(3) on Pd_(4)S with Improved Semi-hydrogenation of Terminal Alkynes

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Precision Chemistry 2024年第5期2卷 200-207页

作者： Wentong Jing Shiguang Mo Weijie Zhang Wenting Zhou Kunlong Liu Jie Wei ruixuan qin Nanfeng Zheng New Cornerstone Science Laboratory State Key Laboratory for Physical Chemistry of Solid SurfacesCollaborative Innovation Center of Chemistry for Energy Materialsand National&Local Joint Engineering Research Center of Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China China Resources Cement Technology R&D(Guangxi)Co Ltd. Nanning 530008China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361102China

Surface modification of metallic nanocatalysts with organic ligands has emerged as an effective strategy to enhance catalytic selectivity,although offten at the expense of catalytic *** this study,we demonstrate a compelling approach by surface modifying Pd2S nanocrystals with PPhz ligands,resulting in a catalyst with excellent catalytic activity and durable selectivity for the semi-hydrogenation of terminal *** and theoretical investigations reveal that the presence of S sites on the Pd surface directs PPh_(3) ligands to preferentially form covalent bonds with S,creating distinctive surface S=PPh_(3) *** configuration induces a partial positive charge on Pd,facilitating hydrogen transfer and thus promoting catalytic ***,the covalent bond between the ligand and catalyst surface forms a robust network,ensuring ligand stability and increasing the hydrogenation energy barrier of ***,the Pd_(4)S@PPhz catalyst exhibits an improved catalytic selectivity with durability in terminal alkyne *** study introduces an effective strategy for designing selective hydrogenation catalysts with an enhanced performance.

关键词： Pd nanocatalysts surface modification selective hydrogenation catalytic stability alkyne semi-hydrogenation

Color center-rich γ-AlOpromotes propane dehydrogenation

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Science China Chemistry 2024年

作者： Yu Wang Xiang Wang Mengfei Qiao qingyuan Wu Kunlong Liu Xiaodong Yi ruixuan qin Gang Fu Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materialsand Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Key Laboratory of the Ministry of Education for Advanced Catalysis Materials College of Chemistry and Material SciencesZhejiang Normal University Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM)

The PtSn/Al2O3catalyst is commonly used in commercial propane dehydrogenation （PDH） processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at high *** Al3+pentahas been proven to be beneficial for enhancing catalytic stability,bottom-up synthesis protocols usually restrict their ***,a facile post-treatment approach using acetic acid was applied to create color centers （electrons trapped within oxygen vacancies） on γ-Al3+***,the content of Alpentawas enriched to 18.3%.Then,the pre-established PtSn clusters were *** electrons facilitated the formation of ultrafine PtSn nanoparticles （～2 nm）,and the Al3+pentasites prevented the sintering of PtSn by constructing the strong Al3+penta–O–Sn ***,the catalytic durability of the catalyst prepared by conventional impregnation methods was remarkably extended from 186 h for the color center-free sample to 1,000 h using the HAc–*** facile post-modification was further successfully extended to commercial Al2O3pellets without altering their mechanical properties,highlighting its potential in industrial applications.

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A facile one-pot synthesis of supercubes of Pt nanocubes

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Science China Chemistry 2016年第4期59卷 452-458页

作者： Dandan Zang Huaqi Huang ruixuan qin Xingli Wang Xiaoliang Fang Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsEngineering Research Center for Nano-Preparation Technology of Fujian ProvinceCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China

A facile one-pot synthetic strategy is developed to prepare high-quality Pt supercubes. The as-synthesized Pt supercubes are composed of the uniform Pt nanocubes arranged in a primitive cubic structure. The shape and size of the Pt superparticles are readily tuned by varying the structures of pyridyl-containing ligands used in the synthesis. The co-presence of CO and nitrogen-containing ligands is critical to the formation of Pt supercubes. While CO molecules play an important role in the synthesis of Pt nanocube, introducing nitrogen-containing ligands is essential to the successful assembly of those nanocubes into Pt supercubes. Our systematic studies reveal that the electrostatic attraction between positively charged ligands and nega- tively charged Pt nanocubes is the main driving force for the assembly of Pt nanocubes into supercubes. More importantly, the ligands within the Pt supercubes are readily removed at relatively low expected to exhibit unique size-selective catalysis. temperature to yield surface-clean supercubes which are

关键词： platinum nanocube supercube self-assembly electrostatic interaction

A vicinal effect for promoting catalysis of Pd1/TiO2:supports of atomically dispersed catalysts play more roles than simply serving as ligands

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Science Bulletin 2018年第11期63卷 675-682页

作者： Pengxin Liu Yun Zhao ruixuan qin Lin Gu Peng Zhang Gang Fu Nanfeng Zheng Collaborative Innovation Center of Chemistry for Energy Materials.State Key Laboratory for Physical Chemistry of Solid Surfaces Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Physics Chinese Academy of SciencesBeijing 100190China Department of Chemistry Dalhousie UniversityHalifaxNS B3H4R2Canada

Atomically dispersing metal atoms on supports has been emerging as an effective strategy to maximize the atom utilization of metals for catalysis. However, due to the lack of effective tools to characterize the detailed structure of metal-support interface, the chemical functions of supports in atomically dispersed metal catalysts are hardly elucidated at the molecular level. In this work, an atomically dispersed Pdl/ Ti02 catalyst with Ti（III） vicinal to Pd is prepared and used to demonstrate the direct involvement of metal atoms on support in the catalysis of dispersed metal atoms. Systematic studies reveal that the Ti （IlI）-O-Pd interface facilitates the activation of 02 into superoxide （02）, thus promoting the catalytic oxi- dation. The catalyst exhibits the highest CO turn-over frequency among ever-reported Pd-based catalysts, and enhanced catalysis in the combustion of harmful volatile organic compound （i.e., toluene） and green- house gas （i.e., methane）. The demonstrated direct involvement of metal atoms on oxide support suggests that the real active sites of atomically dispersed metal catalysts can be far beyond isolated metal atoms themselves. Metal atoms on oxide supports in the vicinity serve as another vector to promote the catalysis of atomically dispersed metal catalysts.

关键词： Support effect Ligand effect Single-atom catalyst Oxidation reaction Superoxide

Air-promoted selective hydrogenation of phenol to cyclohexanone at low temperature over Pd-based nanocatalysts

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Science China Chemistry 2017年第11期60卷 1444-1449页

作者： qing Guo Shiguang Mo Pengxin Liu Weidong Zheng ruixuan qin Chaofa Xu Youyunqi Wu Binghui Wu Nanfeng Zheng Department of Chemical and Biochemical Engineering National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-EstersState Key Laboratory for Physical Chemistry of Solid SurfacesCollaborative Innovation Center of Chemistryfor Energy Materialsand Engineering Research Center for Nano-Preparation Technology of Fujian ProvinceCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Attaining high activity with high selectivity at low temperature is challenging in the selective hydrogenation of phenol to cyclohexanone due to its high activation energy （Ea, 55-70 kJ/mol）. Here we report a simple and efficient strategy for phenol hydrogenation catalyzed by Pd in aqueous phase at 30 ℃ by introducing air to promote the catalysis. With the assistance of air, 〉99% conversion and 〉99% selectivity were achieved over Pd（111）/Al2O3 with an overall turnover frequency （TOF） of 621 h-1, -80 times greater than that of the state-of-art Pd catalyst at 30 ℃. Mechanism studies revealed that phenol was activated to generate phenoxyl radicals. The radicals were yielded from the reaction between phenol and hydroxyl radicals in the presence of hydrogen, oxygen and protic solvent on Pd. The phenoxyl pathway resulted in a low apparent Ea （8.2 kJ/mol） and thus high activity. More importantly, this strategy of activating substrate by air can be adapted to other Pd based catalysts, offering a new thinking for the rational design of cyclohexanone production in industry.

关键词： selective hydrogenation phenol palladium nanocatalysis radical

Surface Coordination Decouples Hydrogenation Catalysis on Supported Metal Catalysts

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CCS Chemistry 2023年第5期5卷 1215-1224页

作者： qingyuan Wu Wenting Zhou Hui Shen ruixuan qin Qiming Hong Xiaodong Yi Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsNational&Local Joint Engineering Research Center for Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005 Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361102

Supported metal catalysts integrating advantages of catalytic hydrogenation and stoichiometric reduction are highly desirable for the green production of fine *** catalytic hydrogenation into H_(2)activation and selective reduction taking place at different locations is expected to provide an effective strategy to fabricate such catalyst ***,we report a decoupled hydrogenation system by modifying Pt catalysts supported on reducible In2O3 with ethylenediamine(EDA).The system exhibits good catalytic performance in oximes production from nitroalkanes,an industrially important reaction,by employing H_(2).Systematic studies demonstrate that the surface coordination of EDA on Pt is crucial to passivate the Pt surface from nitro hydrogenation without inhibiting H_(2)*** activated H_(2)species can then transfer and reduce the In_(2)O_(3)support in situ to generate sustainable stoichiometric reducing agents for the chemoselective reduction of *** upon the mechanistic understanding,a sustainable strategy for the production of oximes has been successfully fabricated.

关键词： hydrogenation catalysis surface coordination reducible support selective hydrogenation of nitro compounds heterogeneous catalysis

Non-contact biomimetic mechanism for selective hydrogenation of nitroaromatics on heterogeneous metal nanocatalysts

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Science China Chemistry 2022年第4期65卷 726-732页

作者： Wenting Zhou Laiyang Li ruixuan qin Jiaxin Zhu Shengjie Liu Shiguang Mo Zaifa Shi Huihuang Fang Pengpeng Ruan Jun Cheng Gang Fu Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materialsand Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

While the enzymatic reduction of unsaturated compounds usually has high specificity,highly selective reduction processes are hardly realized by heterogeneous industrial catalysts,which is critical for the green production of many fine ***,we report an unexpected discovery of a biomimetic behavior of dicyandiamide(DICY)-modified Pt nanocatalysts for the green hydrogenation of a wide range of *** demonstrate that the surface modification by DICY not only prevents the direct contact of nitroaromatic reactants with Pt surface but also induces an effective non-contact hydrogenation mechanism mediated by protons and *** such a process,the DICY layer serves as a“semi-permeable membrane”to allow the permeation of H_(2) molecules for being activated into electrons and protons at the Pt-DICY *** the generation of separated protons and electrons,the nitro group with strong electrophilic properties can be hydrogenated through the electron transfer followed by the proton transfer,which is facilitated by the hydrogen bonding network formed by protonated *** unique mechanism makes it highly directional toward the hydrogenation of nitro groups without side *** to its capability to largely eliminate the waste generation,the developed Pt-DICY catalysts have been successfully applied for the green industrial production of many important aniline intermediates.

关键词： hydrogenation catalysis nitroaromatics proton/electron separation non-contact hydrogenation biomimetic mechanism

Carbon Monoxide Promotes the Catalytic Hydrogenation on Metal Cluster Catalysts

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Research 2020年第1期2020卷 702-710页

作者： ruixuan qin Pei Wang Pengxin Liu Shiguang Mo Yue Gong Liting Ren Chaofa Xu Kunlong Liu Lin Gu Gang Fu Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materialsand National&Local Joint Engineering Research Center for Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China College of Science Huazhong Agricultural UniversityWuhan 430070China Institute of Physics Chinese Academy of SciencesBeijing 100190China

Size effect plays a crucial role in catalytic *** highly dispersed ultrasmall clusters with a limited number of metal atoms are one candidate of the next generation catalysts that bridge the single-atom metal catalysts and metal ***,for the unfavorable electronic property and their interaction with the substrates,they usually exhibit sluggish *** advantage of the small size,their catalytic property would be mediated by surface binding *** combination of metal cluster coordination chemistry brings new *** poisoning is notorious for Pt group metal catalysts as the strong adsorption of CO would block the active *** this work,we will demonstrate that CO could serve as a promoter for the catalytic hydrogenation when ultrasmall Pd clusters are *** means of DFT calculations,we show that Pd_(n)(n=2-147)clusters display sluggish activity for hydrogenation due to the too strong binding of hydrogen atom and reaction intermediates thereon,whereas introducing CO would reduce the binding energies of vicinal sites,thus enhancing the hydrogenation ***,supported Pd_(2)CO catalysts are fabricated by depositing preestablished[Pd_(2)(μ-CO)_(2)Cl_(4)]2-clusters on oxides and demonstrated as an outstanding catalyst for the hydrogenation of *** promoting effect of CO is further verified experimentally by removing and reintroducing a proper amount of CO on the Pd cluster catalysts.

关键词： reaction. hydrogenation introducing