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Zeolite-encaged gold catalysts for the oxidative condensation of furfural

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 67-77页

作者： Weijie li Mingyang Gao Bin Qin Xin Deng landong li School of Materials Science and Engineering Nankai UniversityTianjin 300350China College of Chemistry Nankai UniversityTianjin 300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

The oxidative condensation between renewable furfural and fatty alcohols is a crucial avenue for producing high-quality liquid fuels and valuable furan *** selectivity control in this reaction process remains a significant ***,we report the strategy of confining well dispersed gold species within ZSM-5 structure to construct highly active Au@ZSM-5 zeolite catalysts for the oxidative condensation of *** results and spectroscopy analyses demonstrate the efficient encapsulation of isolated and cationic Au clusters in zeolite ***@ZSM-5(K)catalyst shows remarkable performance with 69.7%furfural conversion and 90.2%furan-2-acrolein selectivity as well as good recycle *** is revealed that the microstructure of ZSM-5 zeolite can significantly promote oxidative condensation activity through confinement *** work presents an explicit example of constructing zeolite encaged noble metal catalysts toward targeted chemical transformations.

关键词： zeolite encapsulation gold oxidative condensation furfural

Conductive catalysis by subsurface transition metals

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National Science Review 2024年第1期11卷 86-93页

作者： Xin Deng Caiyan Zheng Yangsheng li Zeyu Zhou Jiamin Wang Yihua Ran Zhenpeng Hu Fan Yang landong li Frontiers Science Center for New Organic Matter College of ChemistryNankai University School of Physics Nankai University School of Physical Science and Technology Shanghai Tech University School of Materials Science and Engineering Nankai University Haihe Laboratory of Sustainable Chemical Transformations

The nature of catalysis has been hotly pursued for over a century, and current research is focused on understanding active centers and their electronic structures. Herein, the concept of conductive catalysis is proposed and verified by theoretical simulations and experimental observations. Metallic systems containing buried catalytically active transitional metals and exposed catalytically inert main group metals are constructed, and the electronic interaction between them via metallic bonding is disclosed. Through the electronic interaction, the catalytic properties of subsurface transitional metals(Pd or Rh) can be transferred to outermost main group metals(Al or Mg) for several important transformations like semi-hydrogenation,Suzuki-coupling and hydroformylation. The catalytic force is conductive, in analogy with the magnetic force and electrostatic force. The traditional definition of active centers is challenged by the concept of conductive catalysis and the electronic nature of catalysis is more easily understood. It might provide new opportunities for shielding traditional active centers against poisoning or leaching and allow for precise regulation of their catalytic properties by the conductive layer.

关键词： electronic interaction conductive catalysis subsurface transition metal

金属镍活性中心在惰性金属载体中的自分散及其催化炔烃选择加氢性能

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Chinese Journal of Catalysis 2024年第6期61卷 259-268页

作者：邓欣郑彩艳李玮杰王佳敏杨迪胡振芃李兰冬南开大学化学学院有机新物质创造前沿科学中心天津300071 南开大学物理科学学院天津300071 物质绿色创造与制造海河实验室天津300192

单位点催化剂因具有较好的活性、较高的原子利用率和目标产物选择性,在基础科学研究及工业生产领域受到了广泛关注.然而,单位点催化剂的合成策略通常较为繁琐,需要精细调控金属活性中心与载体之间的相互作用.较弱的相互作用可能会导致... 详细信息

单位点催化剂因具有较好的活性、较高的原子利用率和目标产物选择性,在基础科学研究及工业生产领域受到了广泛关注.然而,单位点催化剂的合成策略通常较为繁琐,需要精细调控金属活性中心与载体之间的相互作用.较弱的相互作用可能会导致金属活性位点的迁移和聚集,形成金属团簇,进而引发不必要的副反应.另一方面,过分紧密的相互作用可能会限制金属活性位点的原子效率,从而降低反应活性.本文开发了一种简单通用的自分散策略,用于制备金属态单位点催化剂.该方法利用过渡金属活性中心镍在惰性载体(铝和镁)中的自分散行为,成功构筑了含有孤立过渡金属镍活性中心的全金属催化体系.X射线光电子能谱、低能离子散射和球差矫正扫描透射电子显微镜等表征结果证实了镍/铝催化剂中镍物种以金属态存在,且以孤立状态均匀分布于铝基载体的亚表层.在气固相乙炔选择加氢反应中,镍/铝和镍/镁催化剂表现出较好的催化性能,能够实现100%的乙炔转化率和高乙烯选择性.值得注意的是,镍/铝催化剂在碳碳三键选择加氢反应中的催化性能甚至超越了工业界广泛使用的林德拉催化剂.稳定性测试结果表明,镍/铝催化剂在长达90 h的连续反应中,能够维持稳定的乙炔转化率和乙烯选择性,没有明显的活性下降,进一步印证了其在工业应用中的潜在价值.结合动力学分析、原位红外光谱、氢-氘-乙炔脉冲响应实验以及理论计算等结果,详细阐释了镍/铝催化体系上乙炔选择加氢的反应机制.结果表明,氢气分子优先在镍/铝催化剂表面吸附并发生解离,生成氢原子,随后与乙炔分子逐步反应生成乙烯.在该过程中,氢气的解离活化是整个反应过程的决速步.此外,还进一步探讨了镍/铝催化体系对液相炔烃、炔醇选择加氢的性能,发现该催化剂可以在较为温和的条件下高效催化不同官能团修饰的炔烃、炔醇的选择加氢反应,同时保持高底物转化率和较好的烯烃、烯醇选择性,且表现出较好的循环稳定性.综上所述,本文发展了一种全金属单位点催化体系的通用构筑策略,不仅扩展了单位点金属催化体系的合成方法,同时利用全金属体系的本征优势,为化学转化反应过程提供了新的思路.上述发现为设计合成新型高效催化体系提供了重要的理论和实验依据,有望在精细化学品合成工业中得到应用.

关键词：单位点全金属催化剂选择加氢 Ni基催化剂自分散

分子筛限域单位点钴体系催化芳香族化合物C-H键自调节高效氧化

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Chinese Journal of Catalysis 2024年第2期57卷 133-142页

作者：党健李玮杰秦斌柴玉超武光军李兰冬南开大学化学学院有机新物质创造前沿科学中心天津300071 南开大学材料科学与工程学院天津300350

通过芳香族化合物的碳-氢键活化与选择氧化,可以将廉价芳香烃类原料转化为高附加值含氧产品,因此,该反应在基础研究和工业生产中均受到广泛关注.传统的苯乙酮生产工艺存在毒性底物使用、催化剂回收困难、反应条件苛刻以及产物收率低等问... 详细信息

通过芳香族化合物的碳-氢键活化与选择氧化,可以将廉价芳香烃类原料转化为高附加值含氧产品,因此,该反应在基础研究和工业生产中均受到广泛关注.传统的苯乙酮生产工艺存在毒性底物使用、催化剂回收困难、反应条件苛刻以及产物收率低等问题.通过大量的研究探索,科研人员进一步改进其生产工艺,利用环烷酸钴作为均相催化剂,实现了无溶剂条件下分子氧直接选择氧化乙苯生成苯乙酮.相比均相催化,多相催化在催化剂回收和产物分离方面具有优势,更适合工业化生产.因此,开发用于乙苯选择氧化制苯乙酮的高效稳定多相催化体系非常重要,但具有较大挑战.本文采用原位配体保护的水热合成法将钴配合物(钴-二乙烯三胺)封装在Y型分子筛中,并经进一步焙烧去除配体成功制得Co@Y分子筛催化剂.在无溶剂、无添加剂的条件下,单位点Co作为Co@Y分子筛催化剂的活性位点可催化乙苯选择氧化生成苯乙酮.X射线粉末衍射、透射电镜、紫外可见光吸收光谱和固体核磁共振谱等结果表明,该单位点Co(Co^(2+))通过与骨架氧原子作用稳定限域在Y型分子筛中.为明确Co@Y分子筛催化剂中单位点Co在乙苯氧化反应中所起的重要作用,本文还对比了不同后合成方法所制备的Y分子筛(Co/Y,Co-Y)催化剂及工业环烷酸钴催化剂的催化性能.结果表明,在相同反应条件下,Co@Y分子筛催化剂表现出最高的催化性能,也说明在乙苯氧化反应过程中Co@Y分子筛催化剂的单位点Co有别于上述其他催化剂的活性位点.此外,在Co@Y催化剂热过滤实验中未检测出Co物种浸出,表明Co@Y分子筛催化乙苯氧化反应为多相催化过程,并且在多次循环测试后,Co@Y催化剂结构和反应活性均未发生明显变化.这两项实验均表明Co@Y催化剂具有高稳定性.值得注意的是,在乙苯氧化反应过程中观察到自加速现象,为此进行了对比实验(添加苯甲醛或1-苯乙醇的对比实验)和反应动力学分析.结果表明,痕量苯甲醛或1-苯乙醇的加入会显著改变Co@Y催化剂在乙苯氧化反应中的催化行为,痕量苯甲醛的加入可将反应表观活化能从69.7降至53.7 kJ/mol.本文也通过第一性原理密度泛函理论(DFT)计算系统研究了Co@Y分子筛催化剂单位点Co处乙苯选择氧化反应机理及反应过程中自加速现象产生的原因.DFT计算结果结合上述对比实验和反应动力学分析结果表明,加入痕量苯甲醛或者1-苯乙醇后部分乙苯会直接氧化生成苯乙酮,而非通过乙苯→1-苯乙醇→苯乙酮的途径生成苯乙酮.DFT计算结果也阐明反应过程中自加速现象的产生源于单位点Co处活性氧物种(O^(*))的生成.该活性氧物种在乙苯、苯甲醛和1-苯乙醇的氧化途径中均能自发生成,并且该物种类似“引发剂”促使后续更多链式反应的发生,在乙苯氧化反应过程中具有非常重要的作用.综上所述,本文为理解芳香族化合物碳-氢键选择氧化实验现象与催化作用机制提供了有益见解,可为理性设计开发更高效的催化剂提供新思路.

关键词：碳-氢键活化多相催化 Co@Y分子筛催化剂自加速活性氧物种

Zeolites for separation:Fundamental and application

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Journal of Energy Chemistry 2022年第8期31卷 288-303,I0008页

作者： Bin Yue Shanshan liu Yuchao Chai Guangjun Wu Naijia Guan landong li Haihe Laboratory of Sustainable Chemical Transformations School of Materials Science and EngineeringNankai UniversityTianjin 300350China Frontiers Science Center for New Organic Matter&Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education College of ChemistryNankai UniversityTianjin 300071China

Material based emerging separation techniques are attracting more and more attention as alternatives to the traditional ones such as distillation and extraction,aiming to reduce energy consumption and pollutant *** to their structure characteristics,zeolites can act as versatile sieves and adsorbents for molecules and have been successfully applied in some very important separation ***,two major catalogues of zeolite separations,namely membrane separation and adsorptive separation,are discussed and their underlying mechanisms are *** the part of membrane separation,the synthesis strategies toward zeolite membranes are introduced and the uniformly-oriented zeolite membranes are *** the part of the adsorptive separation,the industrial and popular adsorptive separations with the corresponding zeolite adsorbents are ***,membrane separation relies on the molecular diffusion behavior within zeolites while adsorptive separation relies on the guest–host interaction in *** key challenges and misconceptions in zeolite separations are highlighted throughout the article.

关键词： Zeolite Membrane separation Adsorptive separation Molecular diffusion Guest-host interaction

Propane dehydrogenation catalyzed by in-situ partially reduced zinc cations confined in zeolites

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Journal of Energy Chemistry 2021年第12期30卷 262-269,I0006页

作者： linjun Xie Rui Wang Yuchao Chai Xuefei Weng Naijia Guan landong li School of Materials Science and Engineering Nankai UniversityTianjin 300350China Vacuum Interconnected Nanotech Workstation Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina

Propane dehydrogenation(PDH), employing Pt-or Cr-based catalysts, represents an emerging industrial route for propylene production. Due to the scarcity of platinum and the toxicity of chromium, alternative PDH catalysts are being pursued. Herein, we report the construction of Zn-containing zeolite catalysts,namely Zn@S-1, for PDH reaction. Well-isolated zinc cations are successfully trapped and stabilized by the Si-OH groups in S-1 zeolites via in-situ hydrothermal synthesis. The as-prepared Zn@S-1 catalysts exhibit good dehydrogenation activity, high propylene selectivity, and regeneration capability in PDH reaction under employed conditions. The in-situ partial reduction of zinc species is observed and the partially reduced zinc cations are definitely identified as the active sites for PDH reaction.

关键词： Propane dehydrogenation Zinc catalysts Zn@S-1 In-situ reduction

Catalytic Hydration of Aromatic Alkynes to Ketones over H-MFI Zeolites

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Chemical Research in Chinese Universities 2022年第1期38卷 173-180页

作者： ZHANG Yunzhe DAI Weili WU Guangjun GUAN Naijia li landong School of Materials Science and Engineering Nankai UniversityTianjin 300350P.R.China

The hydration of alkyne represents the most straightforward and simplest route toward the synthesis of ketone. Herein, Brønsted acidic zeolites are explored as potential catalysts for the liquid-phase phenylacetylene hydration. The topology structure and Si/Al ratio are disclosed to be key factors controlling the catalytic activity of zeolites. Typically, H-MFI zeolite with a Si/Al molar ratio of 13 exhibits the highest catalytic activity, with turnover frequency of 6.0 h-1 at 363 K. Besides, H-MFI zeolite shows good catalytic stability and recyclability in the reaction of phenylacetylene hydration, and the substrate scope can be simply extended to other soluble aromatic alkynes. The reaction mechanism of phenylacetylene hydration is investigated by means of kinetic and spectroscopic analyses. The Markovnikov electrophilic addition of phenylacetylene by hydrated protons is established as the rate-determining step, followed by deprotonation and enol isomerization to derive acetophenone product.

关键词： Phenylacetylene Catalytic hydration Zeolite Brønsted acid site H-MFI

Direct hydrothermal synthesis and magnetic property of titanate nanotubes doped magnetic metal ions

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Journal of University of Science and Technology Beijing 2008年第5期15卷 644-648页

作者： Meili Wang Gongbao Song Jian li landong Miao Baoshu Zhang School of Materials Science and Engineering Southwest University of Science and Technology Mianyang 621002 China

Pure titanate nanotubes and titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions were synthesized by the hydrothermal method. In this process,titanate nanotubes were first prepared synchronously with doping Fe^3＋/Ni^2＋/Mn^2＋ ions. The morphology,structure,thermal stability and magnetic property of titanate nanotubes were characterized by X-ray diffraction （XRD）,transmission electron microscope （TEM）,and magnetic measurement. The titanate nanotubes transformed into the anatase titania nanocrystals,and further the mixture of anatase and rutile titania along with increasing temperature. The results indicate that the titanate nanotubes doped with Fe^3＋/Ni^2＋/Mn^2＋ ions are paramagnetic behaviors.

关键词： titanate nanotubes direct hydrothermal synthesis doping magnetic property

Zeolite-encaged mononuclear copper centers catalyze CO2 selective hydrogenation to methanol

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National Science Review 2023年第7期10卷 134-141页

作者： Yuchao Chai Bin Qin Bonan li Weili Dai Guangjun Wu Naijia Guan landong li Key Laboratory of Advanced Energy Materials Chemistry of Ministry of Education College of Chemistry Nankai University CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Materials Science and Engineering Nankai University

The selective hydrogenation of CO2to methanol by renewable hydrogen source represents an attractive route for CO2recycling and is carbon *** catalysts with high activity and methanol selectivity are being vigorously pursued,and current debates on the active site and reaction pathway need to be ***,we report a design of faujasite-encaged mononuclear Cu centers,namely Cu@FAU,for this challenging *** methanol space-time-yield（STY） of 12.8 mmol gcat-1h-1and methanol selectivity of 89.5% are simultaneously achieved at a relatively low reaction temperature of 513 K,making Cu@FAU a potential methanol synthesis catalyst from *** zeolite-encaged mononuclear Cu centers as the destined active sites,the unique reaction pathway of stepwise CO2hydrogenation over Cu@FAU is *** work provides a clear example of catalytic reaction with explicit structure-activity relationship and highlights the power of zeolite catalysis in complex chemical transformations.

关键词： CO2 hydrogenation zeolite methanol catalysis mononuclear copper