Methane hydrates: A future clean energy resource

Natural gas has been considered as the best transition fuel into the future carbon constraint world. The ever-increasing demand for natural gas has prompted expanding research and development activities worldwide for exploring methane hydrates as a future energy resource. With its vast global resource volume (~ 3000 trillion cubic meter CH₄) and high energy storage capacity (170 CH₄ v/v methane hydrate), recovering energy from naturally-occurring methane hydrate has attracted both academic and industry interests to demonstrate the technical feasibility and economic viability. In this review paper, we highlight the recent advances in fundamental researches, seminal discoveries and implications from on-going drilling programs and field production tests, the impending knowledge gaps and the future perspectives of recovering energy from methane hydrates. We further emphasize the current scientific, technological and economic challenges in realizing long-term commercial gas production from methane hydrate reservoir. The continuous growth of the corresponding experimental studies in China should target these specific challenges to narrow the knowledge gaps between laboratory-scale investigations and reservoir-scale applications. Furthermore, we briefly discuss both the environmental and geomechanical issues related to exploiting methane hydrate as the future energy resource and believe that they should be of paramount importance in the future development of novel gas production technologies.     

Attempts to Fill the Gap Between Enzymatic, Homogeneous, and Heterogeneous Catalysis

Bio-inspired and single site metal complex catalysts have been discussed to direct towards a rational design of solid heterogeneous catalysts. When concepts derived from catalytic antibodies, molecular imprinting and molecular recognition, and site isolation and modification by appropriate ligands are combined, with new techniques to prepare, tailor made solid materials, catalysts can be prepared that improve reaction rate and selectivity by increasing the concentration and activation of reactants in the vicinity of the active sites, and by stabilizing transition states or intermediate products. It is also shown that enzymatic, homogeneous and hetergeneous catalysts can be combined to perform “one-pot” cascade reactions.     

反应控制相转移催化环氧化端羟基聚丁二烯的研究

研究了磷钨杂多酸盐反应控制相转移催化双氧水直接环氧化端羟基聚丁二烯(HTPB)的反应,考察了溶剂、H2O2用量、催化剂用量、反应温度、时间、底物质量浓度等因素对环氧化反应的影响。确定了适宜的反应条件为:1,2-二氯乙烷为溶剂,n(H2O2)∶n(底物双键)=1∶1,n(底物双键)∶n(催化剂)=100∶1,反应温度60℃,反应时间6 h,底物质量浓度65 g/L。最适宜反应条件下产物环氧值达8.74 g.100 g-1,催化剂可循环再利用,并表现出较好的稳定性。     

Carbon nanofibers as potential materials for catalysts support,a mini-review on recent advances and future perspective

The element carbon has been used as an active catalyst as well as a catalyst support. This dual nature of carbon has been attributed to its characteristics such as high porosity, large surface area, excellent electron conductivity and chemical inert nature. Besides, the availability of different forms of carbon like graphene, activated carbon, carbon nanotubes and carbon nanofibers have provided carbon a versatile material to be used for different applications. Carbon has been widely used in different applications like electrical, bio-electrochemical, dry cells, electrodes and as a lubricant. However, in the last decades, the catalytic applications of carbon materials especially carbon nanotubes and carbon nanofibers have gained tremendous attention of the researchers worldwide. Carbon nanofibers, in particular due to thier excellent catalytic support profile like, high surface area, thermal stability and its 3D access to the reacting molecules, have been utilized for different chemical reactions. Metal supported on carbon nanofibers have been observed with better activities as compared to the traditional supported counterparts for the several reactions. This mini-review attempts to document the role of carbon nanofibers and their catalytic support profile for the some common chemical processes. The mini-review also suggests about the future innovations and research work for carbon nanofibers as potential future catalysts support.     

When NHC Ligands Make a Difference in Gold Catalysis

Thanks to their unique electronic and steric properties, carbene ligands offer highly valuable features for catalysis, including homogenous gold catalysis. The use of carbene-gold complexes has improved existing reactions, either by modifying reactivity modes or by leading to highly asymmetric processes. These topics will be discussed on the basis of selected examples.     

The Development of Bidentate P,N Ligands for Asymmetric Catalysis

In this review, an attempt is made to systemise the rôle which bidentate phosphinamine (P,N) ligands play in asymmetric catalysis. The ligands will be classified, not by the reaction to which their metal complexes have been applied, but by the nature of their donor atoms. In this manner the development of ligand architectural design can be more easily monitored. The asymmetric transformations to which metal complexes of these ligands have been applied include among others, palladium‐catalysed allylic substitutions, copper‐catalysed 1,4‐additions to enones and rhodium‐catalysed hydroboration of vinylarenes. Excellent enantioselectivities, regioselectivities and reactivities have been achieved in each of these processes.     

相转移催化技术在有机合成中的应用

概述了相转移催化剂的相转移催化原理，相转移催化剂的种类；并以此为基础讨论了相转移催化剂在有机合成及药物合成中的应用。     

有机过渡金属络合物均相催化发展及展望

介绍了国内外均相络合催化的研究及发展,并对均相络合催化的发展方向进行了展望。     

Catalysis in the 21st Century, Lessons from the Past, Challenges for the Future

Catalysis is a science relying on many disciplines. The advent of industrial catalytic technologies in the last century has, most often, resulted from a sequential interaction between chemists and chemical engineers, both communities developing their own fundamental and applied sciences, i.e., a multidisciplinary process. Some of the major lessons learned in the past century, and related achievements, are illustrated and discussed. Challenges for catalysis research in the 21st century are identified, based on the current knowledge of catalysis researchers, recent fundamental and applied developments, and current or long-term objectives of the global chemical industry.     

催化原理课程建设的思考与实践:科学研究与教学过程的融合

现代催化科学与技术快速发展,而催化原理教材内容具有一定的滞后性,因此催化原理课程需要不断改进教学方法和更新教学内容。本文基于研究型教学模式,主张加强科学研究与教学的融合,以实现基本理论、工业应用及最新进展三方面的紧密结合。这种教学模式可以激发学生的学习兴趣,培养学生的主动学习能力和创新意识,符合我校作为石油石化行业研究型大学致力于培养国际一流创新性人才的目标要求。     

Catalysis of Transesterification Reactions by a Self-Assembled Nanosystem

Histidine-containing peptides self-assemble on the surface of monolayer protected gold nanoparticles to form a catalytic system for transesterification reactions. Self-assembly is a prerequisite for catalysis, since the isolated peptides do not display catalytic activity by themselves. A series of catalytic peptides and substrates are studied in order to understand the structural parameters that are of relevance to the catalytic efficiency of the system. It is shown that the distance between the His-residue and the anionic tail does not affect the catalytic activity. On the other hand, the catalytic His-residue is sensitive to the chemical nature of the flanking amino acid residues. In particular, the presence of polar Ser-residues causes a significant increase in activity. Finally, kinetic studies of a series of substrates reveal that substrates with a hydrophobic component are very suitable for this catalytic system.     

相转移催化合成氨基乙酸

以氨水、氯乙酸为原料,以六亚甲基四胺为相转移催化剂,在常温、常压下合成了氨基乙酸。考察了催化剂六亚甲基四胺和温度对合成氨基乙酸反应的影响。在温度５８℃、催化剂用量为氯乙酸的３％、反应原料质量配比为氨水∶氯乙酸＝１∶５的条件下,产品收率为６８８％,纯度达９９６％。     

Ceria-Supported Vinylpyridine Polymers: Synthesis,Characterization and Application in Catalysis

A simple, one-step synthesis of 4-vinylpyridine polymer crosslinked with 2% divinylbenzene [poly(4vp-dvb)] anchored with ceria nanocrystals via in situ reactions that involve simultaneous formation of the polymer and ceria nanocrystals is presented. The polymer support is formed by free radical suspension polymerization of the monomers, while ceria nanocrystals are generated from CeCl₃·7H₂O by the homogeneous precipitation method in a single pot. The polymer supports were characterized by XRD, TEM, SEM, ESCA, and TGA and then tested for their ability as heterogeneous recyclable catalysts in a Biginelli reaction. The catalytic activities of these supports were found to be far superior to the two-step conventional one and simultaneous microporous bead counterparts. Reusability is an added advantage over the other regularly used cerium-based catalysts in aqueous media. The significant increase in the catalytic activity is due to the higher Ce/N ratio and predominance of well-defined and more reactive exposed planes of ceria nanocrystals on the new supports. Such catalysts are of great importance due to environmental, practical and economical concerns.     

Amphiphilic Block Polypeptide‐Type Ligands for Micellar Catalysis in Water

Novel amphiphilic block polypeptide ligands were synthesized and showed excellent behavior in the metal‐catalyzed organic transformations in pure water. The catalytic activity and/or recycling properties of the catalysts are the result of the micellar structure of the polymeric system in water.     

铜钨钼硅多元取代多金属含氧簇合物的合成、性质及催化作用

合成了一个系列的铜钨钼硅多元取代多金属含氧簇合物 :K4H2 [Cu( OH2 ) Si Mo11-n Wn O39].x H2 O　 ( n=2 ,5 ,7,9;x=2 1～ 2 3 ) ,通过 IR,UV,XPS,TG- DTA,XRD对其性能进行了表征 ,并以H2 O2 的反应体系 ,考察了合成的簇合物对 H2 O2 的催化分解作用     

Catalysis of the oxidation of 1,4-cyclohexadiene to benzene by electroactve binuclear rhodium complexes

Electrochemical oxidation of Rh₂(TMB) ₄ ²⁺ (TMB = 2,5-diisocyano-2,5-dimethylhexane) in the presence of 1,4-cyclohexadiene produces benzene and two protons. It is probable that a key step in the reaction is hydrogen-atom transfer from 1,4-cyclohexadiene to electrochemically generated Rh₂(TMB) ₄ ³⁺ . The H-atom abstraction apparently is facilitated by the presence of a d* hole in the Rh ₂ ³⁺ ₂ complex.     

低温等离子体协同催化脱除NOx技术研究进展

利用低温等离子体协同催化脱除氮氧化物(NOx)是目前比较有吸引力和发展前景的技术。本文介绍了低温等离子体协同催化脱除NOx技术的反应机理及研究现状。分别讨论了等离子体的外加电压、等离子体内部结构、温度、还原剂和氧化剂、气体组分以及系统优化等因素对NOx脱除效率的影响,并对该技术进行了展望。     

催化剂载体—硅胶在催化反应中的应用

本文主要介绍了硅胶载体在催化反应中的一些应用。文中所说的催化反应主要有氧化反应、加氢反应、脱氢反应、氢甲酰化反应、烷基化反应等等。     

微生物催化在靛蓝及靛蓝类色素生产中的应用

靛蓝及靛蓝类色素的微生物催化合成因其环境友好、安全稳定等优点成为当前的研究热点。本论文从基因工程、诱变育种、发酵工艺、辅酶再生及双液相催化的应用方面,对微生物法合成靛蓝及靛蓝类色素的技术应用进行阐述,并结合微生物合成靛蓝方面的实际应用,为靛蓝及靛蓝类色素的微生物合成的产业化应用提供指引。