Titanium-Containing Mesoporous Materials：Synthesis and Application in Selective Catalytic Oxidation

Titanium-containing mesoporous molecular sieves are of great significance in selective catalytic oxidation processes with bulky molecules. Recent researches and developments on the designing and synthesis of Ti-containing mesoporous materials have been reviewed. Various strategies for the preparation of Ti-containing rnesoporous materials, such as direct synthesis and post-synthesis, are described. Modifications of Ti-containing mesoporous materials by surface-grafting and atom-planting are also discussed. All approaches aimed mainly at the improving of the stability, the hydrophobicity, and mostly the catalytic activity. Structural and mechanistic features of various synthetic systems are discussed. Ti-containing mesoporous materials in liquid phase catalytic oxidation of organic compounds with H2O2 as an oxidant is briefly summarized, showing their broad utilities for green synthesis of fine chemicals by catalytic oxidative reactions.     

Structure-catalytic functionality of size-facet-performance in pentlandite nanoparticles

As one of the pentlandites,Fe₅Ni₄S₈(FNS) based materials have attracted increasing attention due to their excellent catalytic properties and promising applicability.The control over the catalyst surface structure often benefits its heterogeneous catalytic activity.However,this has not been investigated for FNS materials at the nanoscale regarding the catalytic activity related to high-index facets.Herein,FNS nanoparticles(FNSNPs) with enclosed continuous tunable ...     

Robust and easily retrievable Pd/Ti_3C_2T_x■graphene hydrogels for efficient catalytic hydrogenation of nitroaromatic compounds

Ti_3C_2T_x has been emerging as an attractive platform to prepare composite catalysts,and their assembly into integrated catalytic mate rials repre sents a key step forward toward practical applications.Howeve r,the swelling behavior of Ti_3C_2T_x leads to significant structure change,which challenges the stability of Ti_3C_2T_x-based integrated functional materials for catalytic applications.Here we report a facile synthesis of Pd/Ti_3C_2T_x■graphene hydrogels in which Pd/Ti_3C_2T_x are spatially encapsulated in the 3 D porous graphene framework.The porous interconnected structure not only affords efficient mass transfer and desirable functional accessibility to catalytic active sites,but also effectively buffers the swelling behavior of Ti_3C_2T_x.When applied for catalytic hydrogenation of nitroaromatic compounds,the mechanically robust Pd/Ti_3C_2T_x■graphene hydrogels exhibit efficient activities,easy separability,and good cyclability.This work is expected to promote the application of Ti_3C_2T_x-based functional materials for practical applications involving interactions with salt solutions,such as supercapacitors,catalysis,and water purification.     

Unravelling the role of boron dopant in borocarbonitirde catalytic dehydrogenation reaction

Borocarbonitride(BCN) materials are newly developed metal-free catalytic materials exhibiting high selectivity in oxidative dehydrogenation(ODH) of alkanes. However, the in-depth understandings on the role of boron(B) dopants and the intrinsic activities of –C=O and –B–OH still remain unknown.Herein, we report a series of BCN materials with regulable B content and surface oxygen functional groups via self-assembly and pyrolysis of guanine and boric acid. We found that the B/C ratio is the key pa...     

Engineering d-band states of (CuGa)xZn1-2xGa2S4 material for photocatalytic syngas production

The d-band states of catalytic materials participate in adsorbing reactive intermediate species and determine the catalytic behaviors in CO₂reduction reactions. However, surface d-band states relating to the photocatalytic CO₂reduction reactions behaviors are rarely concerned. Herein, a slightly amount of Cd²⁺is decorated on the surface of(CuGa)_xZn_1-2xGa₂S₄ material(Cd²⁺/(CuGa)_xZn_1-2xGa<...     

Carbohydrate-derived porous carbon materials: An ideal platform for green organic synthesis

Porous carbon materials have attracted much attention in the field of organic synthesis in recent years,due to their tunable properties, excellent catalytic activity and stability. Biomass-based carbohydrates emerge as an ideal precursor for the generation of these materials owing to their renewability, low cost,non-toxicity and high content of functional groups. Thus, carbon materials prepared from carbohydrates is of considerable importance for the sustainable development of organic chemistry....     

Efficiently photothermal conversion in a MnOx-based monolithic photothermocatalyst for gaseous formaldehyde elimination

Volatile organic compound（VOC） pollution has a serious impact on human and urgently needs to be controlled through the development of new methods and catalytic materials. Compared with traditional thermal catalytic oxidation, the synergistic photothermocatalysis is regarded as a green and environmentally friendly strategy for organic compound pollutant removal, which can promote spontaneous heating of the surface of catalysts to achieve thermal catalytic reaction conditions via harvesting light ...     

Effect of the graphitic degree of carbon supports on the catalytic performance of ammonia synthesis over Ba-Ru-K/HSGC catalyst

A series of high surface area graphitic carbon materials （HSGCs） were prepared by ball-milling method. Effect of the graphitic degree of HSGCs on the catalytic performance of Ba-Ru-K/HSGC-x （x is the ball-milling time in hour） catalysts was studied using ammonia synthesis as a probe reaction. The graphitic degree and pore structure of HSGC-x supports could be successfully tuned via the variation of ball-milling time. Ru nanoparticles of different Ba-Ru-K/HSGC-x catalysts are homogeneously distributed on the supports with the particle sizes ranging from 1.6 to 2.0 nm. The graphitic degree of the support is closely related to its facile electron transfer capability and so plays an important role in improving the intrinsic catalytic performance of Ba-Ru-K/HSGC-x catalyst.     

Multi-functional sites catalysts based on post-synthetic modification of metal-organic frameworks

Multi-functional sites MOFs have been explored as a new type of heterogeneous catalytic materials, which can be constructed by various post-synthetic modifications.     

Research perspectives for catalytic valorization of biomass

<正>Efficient utilization of biomass for the supply of energy and synthetic materials would mitigate the heavy reliance on fossil resources and the growing CO₂ emission, thus contributing to establishing sustainable and carbon–neutral societies. Much effort has been devoted to catalytic transformations of lignocellulosic biomass, the most abundant and nonedible form of biomass,     

锌活化Fe/Co/N掺杂的生物质碳基高效氧还原催化剂

为了推动清洁能源-燃料电池的广泛应用, 迫切需要研发成本低、 原料来源广泛的过渡金属基高效氧还原反应(ORR)催化材料, 来替代目前使用的贵金属铂基催化材料. 本文以铁和钴等非贵金属离子作为催化材料的主要活性位点, 通过金属-羧基/羟基螯合键原位预锚定在具有三维(3D)孔道结构、 富含羧基和羟基以及极易在水溶液中形成凝胶网络的海洋生物质材料海藻酸钠上, 经冷冻干燥得到气凝胶; 然后通过高温碳化, 得到活性位点均匀分布在具有多级孔结构的碳骨架中的高活性、 高稳定的Co/Zn/Fe/N@bio-C-2氧还原催化剂材料, 该催化剂包含2种不同的铁基活性材料(Fe₂O₃和Fe)以及2种不同的钴基活性材料(CoO和Co).利用硝酸锌作为活化剂来改善催化材料的孔道结构, 使制备碳材料的总面积从149.3 m²/g增加到325.3 m²/g. 通过一系列对比实验发现, Fe/Co双活性位点与合适比表面积的协同作用使得Co/Zn/Fe/N@bio-C-2获得了最佳的ORR催化活性.其在0.1 mol/L KOH溶液中起始电位达到0.99 V, 半波电位可达0.87 V.     

电解水催化材料动态构效关系的原位拉曼研究进展北大核心CSCD

可再生能源电解水产氢对于实现碳中和目标和未来可持续社会的发展具有重要意义。然而,在电解水服役过程中,催化材料往往会发生复杂的结构演变,这对深入理解电解水催化材料反应机制和精准设计高效催化材料造成了挑战。原位电化学拉曼表征技术对催化材料结构动态演变过程的实时监测,是揭示电解水材料动态构效关系,解析催化反应机理的关键。本文介绍了原位电化学拉曼表征技术的基本原理,重点综述了其在催化材料相结构演变、表面活性位点和界面水分子行为中的最新进展,阐述了电解水催化材料在服役过程中结构演变与性能演变之间的变化规律,为实现催化材料全生命周期动态构效关系的精准构建提供了技术基础。最后,分析总结了原位电化学拉曼表征技术在电解水应用过程中存在的问题与挑战,并对先进原位电化学拉曼技术未来的发展进行了展望。     

二氧化铈表面氧的活化及对氧化反应的催化作用

稀土催化材料的研究和发展为La和Ce等高丰度稀土元素的高质、高效利用提供了有效的途径．Ce基催化剂由于具有优异的储放氧性能,在氧化反应中得到广泛应用．本文介绍了采用理论模拟的方法,在研究Ce的4f轨道和结构弛豫对CeO2氧空位的形成和迁移中的作用以及作为载体时助催化作用的最新研究成果,提出了铈锆固溶体高储放氧性能的本质原因,为进一步制备高性能的氧化铈基储放氧材料和催化剂提供了理论基础．同时,对铈基催化剂在甲烷催化燃烧、CO催化氧化和卤代烃催化燃烧等反应中的应用和催化作用进行了综述,重点讨论了CeO2及其复合催化剂的氧化还原性能与其活性之间的关系．最后对在铈基催化剂研究中存在的问题和发展思路提出了思考和展望．     

Trial Test of Supported Nanosized Catalyst in Catalytic Reformate Hydrotreating Reaction

Nanostructured particles are a new kind of materials whose size is less than 100 nm. It is obvious that the properties(e.g. electronic, magnetic, catalytic, optical and themal etc) of nano-particles are more excellent than those of traditional materials because of high specific surface area and special structure. Up to now, nano-particles have been studied and will be developed as a new kind of catalysts in the oil and chemical industry as well as environment protection fields. In this paper, catalytic properties of the nano-Pd/Al₂O₃ catalyst were studied for catalytic reformate hydrotreating reaction.     

MoS2/WS2‐Graphene Composites through Thermal Decomposition of Tetrathiomolybdate/Tetrathiotungstate for Proton/Oxygen Electroreduction

MoS₂ and WS₂ have been prepared on a conductive graphene support by thermal reduction of tetrathiotungstate/tetrathiomolybdate and graphite oxide. Whereas the catalytic properties towards hydrogen evolution are strongly influenced by the Magnéli phases formed as a byproduct during the synthesis, the catalytic activity towards oxygen reduction of these composite materials is not affected by this phenomenon and these materials exhibit high catalytic activity towards this industrially important reaction.     

离子液体功能化金属/共价-有机框架材料在催化反应中应用

离子液体（ILs）功能化的金属有机框架（MOFs）和共价有机框架（COFs）材料兼具离子液体和MOFs/COFs的优点，是一种极具潜力的复合催化材料。MOFs和COFs材料固定的孔结构及较大的比表面积为负载高分散催化中心提供了天然的物理空间；多孔结构促使催化剂与反应物充分接触；丰富的孔道有利于运输催化反应底物和产物，进而实现催化反应的高效进行。特别是离子液体片段的引入，可以作为催化活性中心的配体（稳定剂）或分散剂，同时能够有效改善MOFs和COFs材料孔道和活性中心周围的微环境。此外，还可以充分利用离子液体片段在适当的反应条件下转化为氮杂环卡宾配体的特点，在MOFs和COFs材料中引入氮杂环卡宾有机金属配合物。因此，我们对近几年来离子液体功能化的MOFs或COFs催化体系在CO2环加成、CO2还原、C-C偶联、羰基化以及其它有机转化反应中的研究应用进行简要综述。并对复合材料在催化领域的发展进行总结和展望。     

富氧条件下Ir催化NO反应

用浸渍法制备了系列Ir催化剂, 研究了富氧条件下Ir催化NO的反应, 考察了催化剂的催化反应性能及负载量和载体对催化活性的影响. 结果表明, 在Ir催化剂上不仅发生了NO氧化反应, 同时也发生了NO还原反应; Ir催化剂对NO反应有催化作用, 催化活性随Ir负载量的增加而增强. 载体对催化剂活性有一定的影响, 负载量低于0.1%(w)时, 催化NO氧化的活性顺序为Ir/ZSM-5>Ir/γ-Al2O3>Ir/SiO2, 这主要受载体自身性质的影响; 负载量高于0.1%时, 催化NO氧化的活性顺序为Ir/ZSM-5>Ir/SiO2>Ir/γ的活性顺序为Ir/γ-Al2O3>Ir/SiO2>Ir/ZSM-5, 这主要由于载体吸附作用促进了NO2在Ir催化剂上吸附分解. 与Pt催化剂相比, Ir催化剂更有利于促进NO还原.     

介孔钛硅新催化材料

本文综述了介孔钛硅新催化材料的制备方法,归纳评述了各类介孔钛硅材料的制备技术和相应的产物的结构特点,介绍了现有的表征介孔钛硅材料孔结构和钛活性位的重要技术手段和特征,概括了含钛介孔材料在有机物液相催化选择氧化方面的应用,讨论了提高钛位的催化活性、结构稳定性、疏水性、钛硅比等的技术方法;提出了介孔钛硅材料研究存在的问题并展望了将来的研究方向。     

光/高能诱导纳米TiO2及其同系物催化新进展

文章从催化原理、制备方法、影响光/高能诱导催化反应的各种因素,提高纳米TiO2系催化剂催化活性途径及实际应用等方面,对光/高能诱导纳米TiO2及其同系物催化进行了综述。     

Self-assembled Nanohybrid from Opposite Charged Sheets: Alternate Stacking of CoAl LDH and MoS_2

Hybrid materials are attracting intensive attention for their applications in electronics, photoelectronics, LEDs, field-effect transistors, etc. Engineering new hybrid materials and further exploiting their new functions will be significant for future science and technique development. In this work, alternatively stacked self-assembled CoAl LDH/MoS_2 nanohybrid has been successfully synthesized by an exfoliation-flocculation method from positively charged CoAl LDH nanosheets(CoAl-NS) with negatively charged MoS_2 nanosheets(MoS_2-NS). The CoAl LDH/MoS_2 hybrid material exhibits an enhanced catalytic performance for oxygen evolution reaction(OER) compared with original constituents of CoAl LDH nanosheets and MoS_2 nanosheets. The enhanced OER catalytic performance of CoAl LDH/MoS_2 is demonstrated to be due to the improved electron transfer, more exposed catalytic active sites, and accelerated oxygen evolution reaction kinetics.