富勒烯类炭材料作为新型载体在多相催化中的应用

评述了富勒烯类新型炭材料作为金属催化剂的载体在多相催化领域中的潜在应用途径。首先概要介绍这些炭材料在均相和多相催化中一些应用实例,然后分别详细分绍C60分子化合物、单壁纳米炭管和多壁纳米炭管等富勒烯类新型炭材料的催化性能及其应用。     

Model catalysis by metals and alloys: From single-crystal surfaces to well-defined nano-particles

During the last decades surface science has played an important role for modelling surface chemistry on metallic surfaces and understanding catalytic processes for simple reactions. Progresses are now made possible by the recent development of specific tools for characterising at the nanoscale level model materials and following the kinetics of reactions on these materials of small area in dedicated reactors.It needs the preparation, and characterisation at the atomic level, of well-defined materials. They can be either single-crystal surfaces having a well-defined orientation or in shape of model supported nano-particles. Most has been done in the framework of monometallic materials, but more difficult is the preparation of well-defined alloy surfaces and surface alloys, and the elaboration of alloy nano-particles well-defined in size and composition.Kinetic studies in dedicated reactors show how the catalytic behaviour of model samples may depend on the specific sites present at surface. For example, surface sites having a low coordination number (like steps, kinks, edges and corners) are very efficient for bond-breaking. In bi-metallics, ad-layers of a given metal on a foreign substrate may show new and original structures having very specific catalytic properties. Thus, works on catalysis at the atomic scale proposes new active/selective sites, and it is now a challenge to design new industrial catalysts on the basis of these fundamental works.In order to move near the conditions for real catalysis one has now to bridge the “pressure gap”, i.e. to make in situ (during reaction under pressure of reactants) characterisation of both the surface itself and ad-species. This needs the development of specifics tools able to work in such conditions. This is a challenge for today and future works in the field of model catalysis.     

The impact of surface science on the commercialization of chemical processes

Surface science developed instruments for atomic- and molecular-scale studies of catalyst surfaces, their composition and structure, both in a vacuum and at high pressures, under reaction conditions (bridging the pressure gap). Surfaces ranging from single crystals, nanoparticles and thin films to porous high surface area catalytic materials have been studied. Classes of surface structure sensitive and insensitive reactions have been identified by surface science studies, including ammonia synthesis, hydrodesulfurization, reforming, combustion and hydrogenation. Rates of reactions often vary by orders of magnitude between using the right and the wrong surface structures. The roles of many promoters that modify the catalyst surface structures and bonding of adsorbates have been verified. Surface reaction intermediates could be identified and the mobility of adsorbates and the adsorbate induced reconstruction of the catalysts attest to the dynamic nature of the catalytic systems during the reaction turnover. The important active sites for catalysis include the low coordination surface step, kink, oxygen and chloride ion vacancies sites and sites at oxide-metal interfaces. Uncovering the molecular ingredients of heterogeneous catalysts will have a major impact on the understanding of reaction selectivity to help the evolution of green chemistry and selective reaction of many types.     

Asymmetric Heterogeneous Catalysis: Science and Engineering

Asymmetric heterogeneous catalysis is a vivid branch of catalysis, remaining, however, largely a domain of organic chemists. The view towards asymmetric heterogeneous catalysis adopted in this review is mainly from catalytic science and engineering. Not only reaction mechanisms, but also catalytic properties, kinetic regularities, as well as chemical engineering aspects, are covered with the main focus on recent developments.     

Asymmetric Heterogeneous Catalysis: Science and Engineering

Asymmetric heterogeneous catalysis is a vivid branch of catalysis, remaining, however, largely a domain of organic chemists. The view towards asymmetric heterogeneous catalysis adopted in this review is mainly from catalytic science and engineering. Not only reaction mechanisms, but also catalytic properties, kinetic regularities, as well as chemical engineering aspects, are covered with the main focus on recent developments.     

Process systems engineering studies for the synthesis of catalytic biomass-to-fuels strategies

The goal of this paper is to show how chemical process synthesis and analysis studies can be coupled with experimental heterogeneous catalysis studies to identify promising research directions for the development of strategies for the production of renewable fuels. We study five catalytic biomass-to-fuels strategies that rely on production of platform chemicals, such as levulinic acid and fermentable sugars. We first integrate catalytic conversion subsystems with separation subsystems to generate complete conversion strategies, and we then develop the corresponding process simulation models based on experimental results. Our analyses suggest that catalytic biomass-to-fuel conversion strategies could become economically competitive alternatives to current biofuel production approaches as a result of iterative experimental and computational efforts.     

Last Decade of Research on Activated Carbons as Catalytic Support in Chemical Processes

This review is devoted to the application and knowledge developed in the past 10 years in the area of chemical processes catalyzed by activated carbon supported catalysts. Activated carbons are well known for their catalytic properties and for being used as support in heterogeneous catalysis. The supported catalysts have been successfully used in the chemical industries for long time. In the last decade, carbon supported catalysts have opened the door for new chemical catalytic processes based on their intrinsic features. However, fundamental understanding of molecular structure-reactivity relationship of these carbon materials remains unexplored. Futures advances in all areas may be possible through combined experimental and theoretical approaches.     

掺杂多孔碳材料催化硝基苯还原反应的研究进展

苯胺是重要的化工原料和合成中间体,通过硝基苯的催化还原反应可以方便地制备苯胺类化合物。多孔碳材料因其高比表面积、发达的孔隙结构和容易回收等特点在催化领域越来越受到重视,然而其应用受到自身活性位点缺乏和化学惰性的限制。杂原子掺杂可以增强碳材料的表面极性,调节电子结构,改善其催化性能,可作为硝基苯催化还原反应的有效催化剂。本文对近年来掺杂多孔碳材料在硝基苯催化还原反应中的研究进展进行了总结。本文概述了氮掺杂型多孔碳材料、共掺杂型多孔碳材料、负载贵金属的掺杂多孔碳材料和负载廉价金属的掺杂多孔碳材料这4种主要的掺杂多孔碳材料的制备方法,并详细介绍了不同掺杂多孔碳材料在催化硝基苯催化还原反应时的催化性能、可能的催化活性位点以及催化机理。最后,指出目前掺杂多孔碳材料催化硝基苯还原还需要解决反应选择性、催化剂催化活性和生产成本等问题,以生物质为前体,开发共掺杂型和二元双金属负载的掺杂多孔碳材料是未来的重要发展方向之一。     

神经网络全局势函数在多相催化中的应用

当今的多相催化研究需要新的技术和方法从原子尺度上表征活性中心结构和反应中间体。本文作者课题组近期开发了理论模拟新技术来探索催化剂活性位点结构,即基于神经网络势函数的大规模原子模拟（LASP）软件中实现的全局神经网络势函数计算方法。本文介绍了该方法可以显著降低催化体系的计算代价,而维持与密度泛函理论同一级别的计算精度,从而解决多相催化中的许多复杂问题。本文对神经网络势函数方法的实现细节和目前已实现的应用场景进行了详细介绍。神经网络势函数可以用来预测材料晶体结构,理解高压氢化条件下TiO₂表面的结构演化和确定三元氧化物ZnCrO晶相中合成气制甲醇活性位点。最后文章分析了神经网络势函数的局限性和今后可能的三个研究方向,即材料性质预测、多元素体系神经网络势函数构造和化学反应拟合。     

MOFs基多孔液体的制备及其应用

多孔液体(Porous Liquids, PLs)是一种结合了多孔固体材料永久孔隙率和液体流动性的新型液体材料,在气体吸附和分离、催化等应用领域中展示出巨大的潜力。金属框架材料(MOFs)因其具有高的比表面积、热和化学稳定性、独特的结构以及制备简单的特点,使其有望成为构筑PLs多孔宿主的最佳候选材料之一。近些年来,基于MOFs(ZIF-8、ZIF-67、UiO-66等)基多孔液体相关研究被陆续报道。首先,介绍了多孔液体的分类;其次,总结了近些年来MOFs基多孔液体的制备以及应用;最后,对MOFs基多孔液体的制备存在的挑战与未来在气体吸附、催化等领域进行了展望与总结。     

The Role of Catalysis in Determining Men’s Quality of Life

Modern civilization, whose spectacular development took place in the second half of XX century as the result of scientific and information revolution has six characteristic features: (1) it is a mass civilization, (2) it is mobile, (3) it is global, (4) it is free of the spectre of famine, (5) it is built on informatics, (6) human lifespan is steadily prolonged. In order to achieve these goals it was necessary to invent thousands new materials and to find out methods of their fast and cheap production in large quantities. The unique possibility of the fast and selective production of the desired chemical molecules, required to obtain a material with defined properties, is offered by catalysis. Catalysis comprises technological processes of the largest scale, such as catalytic cracking of billions tons of crude oil per year and smallest scale enzymatic reactions with micrograms of product formed with 100% chemo-, regio- and stereoselectivity. With the rapidly growing earth’s population increasingly important becomes not only the production of materials needed in our modern society, but also the destruction of undesired by-products of its activities, making the application of catalysis to pollution control one of important tasks. The progress of catalysis, both science and technology, was in the last 50 years driven by the development in five fields: (1) new materials, particularly those based on the principle of molecular imprinting (use of templates), (2) application of new surface science techniques to identify active sites and surface reaction intermediates, (3) quantum chemical modeling of elementary steps of catalytic reactions, (4) design of new reactors, (5) development of computational catalysis, (6) development of new ways for carrying catalytic reactions, (7) biocatalysis using enzymes, modified by mutagenesis and recombination techniques to make them selective and active in conditions of the desired technological process. Application of molecular sieves, catalytic antibodies, metallocene catalysts, asymmetric catalysis, fuel cells, control of automotive exhaust are described and pending change of the paradigm of catalysis is discussed.     

锰氧八面体分子筛的制备及应用研究进展

锰氧八面体分子筛具有多孔结构、温和的表面酸碱性、混合价态的锰离子和优异的离子交换性,被广泛应用于多相催化、电池材料和吸附材料等领域。本文介绍了锰氧八面体分子筛的化学组成,对其孔结构、氧化还原性能及酸碱性等理化性质予以总结,简述了水热法、回流法、微波法、溶胶-凝胶法和固相法等常用制备方法。锰氧八面体分子筛可应用于CO催化氧化、有机物催化氧化、CO₂活化利用和费托合成等催化领域,尤其对CO和挥发性有机物有较高的氧化活性,在电池材料和吸附材料等非催化领域也有重要的应用前景。最后指出了当前锰氧八面体分子筛研究中存在的问题,未来工作应探索更高效的合成方法,深入认识其催化作用机理,进一步拓宽该材料的应用范围。     

Fundamental Investigations of Enantioselective Heterogeneous Catalysis

Enantioselective heterogeneous catalysis is an important and rapidly expanding research area. The two most heavily researched examples of this type of catalysis are the enantioselective hydrogenation of α-ketoesters over Pt-based catalysts and the enantioselective hydrogenation of β-ketoesters over Ni-based catalysts. These systems share one extremely important common feature—the enantioselective surface reaction is controlled by the presence of adsorbed chiral molecules (modifiers) on the surface of the metal component of the catalyst. In each system, a number of models have been proposed to explain the enantioselective behavior in the light of catalytic experiments. In recent years, surface science has begun to address the issues relevant to this branch of catalysis. This article reviews to what extent surface science has enabled the verification of the proposed models and, in addition, what new light surface science has shed on the possible mechanisms of enantioselective heterogeneous catalysis.     

金属材料协同VB12催化卤代有机物降解研究进展

卤代有机物（HOCs）是环境领域的主要污染物类型之一，因其高持久性、毒性和生物累积性而受到广泛关注。还原脱卤技术是一种高效、低耗、易行的HOCs处理方式，而生物辅酶因子维生素B₁₂（VB₁₂）对HOCs的还原脱卤有很高的催化活性。本文总结了单金属、双金属、金属矿物及半导体等金属材料协同VB₁₂催化降解HOCs的研究进展，讨论了每种金属材料与VB₁₂的协同催化机制、降解HOCs机理特性、实际应用情况及局限性等。结果表明，金属材料协同VB₁₂对HOCs还原脱卤具有加速电子转移、金属表面介导催化、活化碳-卤键等独特的优势和广阔的应用前景。最后，结合最新研究，指明目前该体系在机理研究、材料设计、实际应用、技术等方面所面临的挑战及未来的研究方向。     

核壳结构纳米复合材料的制备及催化应用研究进展

核壳结构纳米复合材料，即一层或多层的无机或有机材料借助某种相互作用力包覆在无机或有机颗粒的外表面所形成的具有核壳结构的纳米材料。核壳结构纳米复合材料可以改善外壳和内核的不足，提高材料的光、电、磁、催化等特性。根据核和壳层的不同可划分出多种分类，且制备方法多样。核与壳之间的相互作用促使核壳结构纳米复合材料呈现出多种优异的功能特性，广泛应用于诸多领域。在催化中，核壳结构纳米复合材料不但表现出良好的耐化学侵蚀特性还能有效减少纳米粒子的团聚、烧结等问题。该文综述了核壳型纳米复合材料的分类、制备方法及在催化领域中的应用，简单阐述了其形成机理，并对其未来发展方向进行了展望。     

核壳结构纳米复合材料的制备及催化应用研究进展

核壳结构纳米复合材料,即一层或多层的无机或有机材料借助某种相互作用力包覆在无机或有机颗粒的外表面所形成的具有核壳结构的纳米材料。核壳结构纳米复合材料可以改善外核和内壳的不足,提高材料的光、电、磁、催化等特性。根据核和壳层的不同可划分出多种分类,且制备方法多样。核与壳之间的相互作用促使核壳结构纳米复合材料呈现出多种优异的功能特性,广泛应用于诸多领域。在催化中,核壳结构纳米复合材料不但表现出良好的耐化学侵蚀特性还能有效减少纳米粒子的团聚、烧结等问题。该文综述了核壳型纳米复合材料的分类、制备方法及在催化领域中的应用,简单阐述了其形成机理,并对其未来发展方向进行了展望。     

负载NHC-Pd配合物催化Suzuki偶联反应的研究进展

钯催化的Suzuki偶联反应作为有效的构建碳-碳键的方法,在天然产物、药物全合成和有机合成工业中被广泛应用。而目前广泛应用的含钯均相催化剂尽管反应活性高,但昂贵钯金属盐或配合物不易回收,痕量残留于目标产品或者废液中,导致目标产品重金属污染和环境污染等弊端,极大地增加了该反应的成本和降低了产品的安全性,因此期望以易回收使用、低钯浸出的异相催化剂来实现对该反应的高效绿色催化。氮杂环卡宾钯配合物（NHC-Pd）在催化Suzuki偶联反应中具有反应活性高、稳定好等优点常被用作异相催化剂的催化中心。该文从异相催化剂的载体材料如高分子材料、多孔硅材料、碳基材料、金属-有机框架及磁性纳米粒子等出发,综述了近年来NHC-Pd在异相催化Suzuki偶联反应中的最新研究进展,对于今后该研究方向的开展具有指导意义。     

环境友好的超临界多相催化反应研究进展

在传统的多相催化反应中引入惰性超临界流体的超临界多相催化反应可以改善反应过程或减少环境污染.综述了超临界多相催化反应的特点,并着重从催化超临界水氧化反应、超临界相转移催化反应、超临界酶催化反应等3个方面详细论述了超临界多相催化反应的研究进展.最后对今后的发展方向提出了看法.     

醛与胺均相催化合成三级酰胺研究进展

酰胺类化合物是材料科学、化学生物学及药物化学中重要的有机化合物。醛容易得到且毒性较小,出于原子经济性考虑是合成酰胺的合适原料。近年来,随着绿色化学的兴起,利用醛作为酰化试剂,通过C—H键活化方式合成酰胺键的方法得到广泛关注。研究方法中,有机小分子、过渡金属、稀土盐或配合物的催化起到重要作用,纳米催化剂的催化在酰胺键形成方法的研究也有突破。纳米粒子应用于醛与胺合成三级酰胺的反应有金属胶体纳米催化剂(准均相型)和磁性非均相型。非均相催化剂的优势在于其较高的回收使用率,易与产物分离,便于回收再利用。磁性纳米材料与以往的均相催化剂相比,分离和回收更加简单方便,重复利用率更高,但催化剂表征受到限制。探索制备方法简单、操作步骤方便和催化效果显著的普通多相纳米催化剂是未来应用于催化醛合成酰胺的新领域。综述近年来利用醛作为酰化试剂,通过C—H键活化的方式,与铵盐、二级胺、三级胺和酰胺反应合成三级酰胺化合物的方法,并总结相关反应机理。     

活性氧物种及其检测方法的研究进展

活性氧物种(Reactive Oxygen Species, ROS)是一种具有强反应活性的物质,主要包括超氧阴离子自由基、过氧化氢、单线态氧和羟基自由基等。作为氧化剂的氧气分子较为稳定,需要转化为高反应活性的活性氧物种后才能进一步与其他物质发生反应。在化学反应尤其是催化氧化反应中,活性氧的种类、生成、扩散行为等常常决定着整个反应的进行方向与速率;在生命科学领域,活性氧则参与能量转换、氧平衡等重要生理环节,与衰老、疾病等息息相关。而活性氧因其短寿命、强反应活性等,定性定量测试较为困难。选择合适的检测方式、提高检测的时空准确度,对于多相催化、环境化学、生命科学等领域研究有着重要意义。本工作对活性氧检测方法的基本原理、研究进展,以及在环境、生命领域以及多相催化的应用等方面进行对比与分析,比较各种手段的优缺点及适用范围。并对多相催化中氧物种的模拟及检测手段进行分析,展望了活性氧在催化氧化等领域未来的研究方向。