Supramolecular polymer is a new interdiscipline of supramolecular chemistry and polymer science. In supramolecularly polymeric structures the monomers are connected by noncovalent bonds such as hydrogen bonds, metal-organic coordinations, and host-guest interactions and so on. Supramolecular polymers constructed on the basis of host-guest interactions constitute of a main branch of the whole family of supramolecular polymers. In this review, some representative progress on the construction of supramolecular polymers based on host-guest interactions has been summarized, after a brief introduction of the concept and history of supramolecular polymer. It has been divided into five parts according to the different structures of the host molecules. In the last part, the challenges and prospective tendency of this subject have also been discussed.

Contents
1 Introduction
2 Crown ether and cryptand based supramolecular polymers
3 Cyclodextrin based supramolecular polymers
4 Calixarenes based supramolecular polymers
5 Cucurbiturils based supramolecular polymers
6 Pillararene based supramolecular polymers
7 Conclusion and outlook

Metal ions are commonly seen in naturally occurring protein molecules, and often play pivotal roles in protein function. Deepening understanding of basic coordination models between amino acids and various metals facilitates artificial designs of novel peptide-metal coordination modalities that can be broadly applied in research fields such as peptide structure-function optimization, molecular assembly, labeling and imaging, and peptide therapeutics development. This minireview introduces the basic coordination chemistry between electron-donating groups on peptides (namely carboxylate, amine, imidazole, sulfhydryl groups) and their respective favorable metal ions with illustrated examples. We next discuss in detail the use of metal or metalloid coordination in fundamental research of peptides and proteins, including secondary structure constraining, supermolecular assembly, fluorescence or phosphorescence labeling, and protein folding analysis. In particular, we highlight two examples of luminogenic peptide/protein labeling techniques, the first being the broadly applied biarsenical ligand and tetracysteine motif based protein probing method, and the second being the recently reported iridium(Ⅲ) complex and histidine motif based peptide labeling technique. Finally we discuss the principles in the development of metallo-peptide molecular probes and the potential brought by this research for optimization in drug designs.

Contents
1 Introduction
2 Common binding groups in peptides for metal coordination
2.1 Carboxyl group
2.2 Amine group and imidazole group
2.3 Sulfhydryl group
3 The effects of metal coordination on peptide/protein structure
3.1 Folding and stabilization
3.2 Supermolecular assembly
4 Coordination-based peptide luminescent labeling and biological applications
5 Outlook

Secondary batteries play important roles in energy storage. Secondary batteries such as lithium/sodium-ion batteries are promising for portable electronic devices, electric vehicles and green energy storage. The research on novel electrode materials is important for rechargeable battery of next generation. Phosphorus is attractive as anode materials due to its high theoretical specific capacity and abundant resources. However, there are many unknown aspects of phosphorus materials, which hinders its development and application, especially in the field of energy storage. This paper focuses on the properties of all the allotropes of phosphorus, and briefly introduces the research advances of phosphorus anode in recent years, including preparation, the effects of matrix structure on electrochemical performances and on the mechanisms. Meanwhile, the paper prospects the development trend of phosphorus based composites, aiming at further application in secondary batteries.

Contents
1 Introduction
2 The properties of all the allotropes of phosphorus
3 The research advances of phosphorus anode materials
4 The effect of matrix structure
4.1 Porous carbon
4.2 Nanotube
4.3 Graphene
5 Conclusion

Rechargeable lithium-ion batteries are vital for developing the electronic devices especially for the portable devices, as well as for the rapid development of plug-in hybrid-electric vehicle (PHEV)/electric vehicle (EV). And also, they are good choices for the deployment of power system (peak clipping and valley filling) and introducing the electric power into power system from the renewable energy sources. However, the disadvantages of low energy capacity are often reviled for the traditional lithium-ion batteries. In the past few decades, the researches of seeking substitutes for the traditional graphite anode material, including metal oxide, titanium-, tin- and silicon-based anode materials, have been widely investigated, and their positive effects on the high capacity and rate capability in the lithium half batteries have been demonstrated repeatedly. But to date, there is insufficient data to confirm these effects in lithium-ion full batteries, and very few kinds of anode materials were successfully utilized in commercialization. Thus, the questions of how the development of new anode-based lithium-ion full battery and whether it could be truly commercialized need to be well considered and discussed urgently, as many researchers concerned. At this stage, this review mainly discusses the development of lithium-ion full batteries starting from the irreversible capacity characteristics of anodes (graphite,Li₄Ti₅O₁₂, TiO₂, GeO_x,FeO_x,Sn- and Si-based,etc.) in initial cycles.

Contents
1 Introduction
2 Lithium-ion full batteries based on different anodes
2.1 Anode materials with initial revisable capacity
2.2 Anode materials with initial irrevisable capacity
3 Conclusion

Organohalide lead perovskite solar cell is highly efficient and low cost in the fabrication process. It has attracted much attention and been widely investigated all around the world. This review looks back into the history of the organohalide lead perovskite solar cells (PSCs) and gives a brief introduction of the research progress of the PSCs. It emphatically points out the relationship between the components of the perovskite ( A cation,B cation and X anion ) and its photoelectrical properties. We classify the PSCs into three types, namely sensitized PSCs, meso-superstructure PSCs and planar heterojunction PSCs. What's more, we point out the issues concerned the developments of PSCs. The future directions are also indicated. Finally, as a high-efficiency new comer to the solar cell family, the potential benefits on the human society are expected.

Contents
1 Introduction
2 The history of organohalide perovskite solar cells
3 The relationship between the components of the organometal halide and its photoelectrical properties
4 Organolead halide
4.1 Organolead iodide
4.2 Organolead bromide
4.3 Mixture of different organolead halides
5 Hole transporting material layer
6 Different kinds of organolead halide perovskite solar cells
6.1 Non-planar perovskite solar cells
6.2 Planar heterojunction perovskite solar cells
7 Future direction and interests of organolead halide perovskite solar cells
7.1 Organolead halide perovskite material
7.2 Different production process of perovskite solar cells
7.3 HTM layer and counter electrode
7.4 Planar heterojunction perovskite solar cells
7.5 Large-area solar cells
7.6 The mechanism research of the perovskite solar cells
8 Conclusion and outlook

The use of metal-organic frameworks (MOFs) as heterogeneous catalyst for oxidation reactions developed in recent years is reviewed. Because of their unique structural features and outstanding physical/chemical properties, including metal or organic active sites in pore surface, high porosity, large surface areas, and tailorable pore properties, MOFs are promising and favorable for application in various catalytic reactions. In this review, the applications of MOFs in catalytic oxidation as catalysts or as supports of catalytic active species are discussed. Catalytic MOFs with coordinatively unsaturated metal active sites and MOFs supported metal nanoparticles (MNPs), polyoxometalates (POMs), and metalloporphyrins are emphasized. Catalytic oxidization of varieties of organic molecules, including alkanes, benzylic hydrocarbons, olefins, alcohols, phenols, and sulfur compounds, as well as small inorganic molecules, including CO and water in MOFs and/or MOFs supported catalysts are summarized. In addition, the application of MOFs in the oxidation of organic dyes and biomimetic catalysis is also discussed. Catalytic performances of these MOFs and MOFs supported catalysts are evaluated from the stability, heterogeneity, and shape/size selectivity, as well as precipitation of the active species aspects. Finally, the development trend of MOFs in the catalytic applications is prospected.

Contents
1 Introduction
2 Catalytic oxidation by MOFs
2.1 Oxidation of alkanes
2.2 Oxidation of benzylic hydrocarbons
2.3 Oxidation of olefins
2.4 Oxidation of alcohols
2.5 Oxidation of phenols
2.6 Oxidation of sulfur compounds
2.7 Photocatalytic oxidative degradation of organic dyes
2.8 Other oxidation reactions
3 Catalytic oxidation by MOFs supported catalysts
3.1 Oxidation of CO
3.2 Oxidation of H₂O
3.3 Oxidation of olefins
3.4 Oxidation of alcohols
3.5 Oxidation of sulfur compounds
3.6 Other oxidation reactions
4 Conclusion and outlook

As one of the important parts of the molecular machines, molecular machines driven by acid-base chemistry play the crucial role in molecular machines, and have attracted more and more attentions for the applications in the design and construction of controllable molecular machines. At the same time, owing to the great progresses in theory studies of the molecular machine, several different kinds of functional and practical molecular machines driven by acid-base stimuli have been reported and utilized in supramolecular gels, supramolecular catalysts, supramolecular vesicles, supramolecular nanovalves, supramolecular polymers, and so on. In this paper, the design and applications of acid-base controllable molecular machines based on pseudorotaxanes, rotaxanes, and catenanes are reviewed, and the prospects of such molecular machines are also described.

Contents
1 Introduction
2 Molecular machines driven by acid-base chemistry
2.1 Acid-base driven molecular machines based on pseudorotaxanes
2.2 Acid-base driven rotaxanes-based molecular machines
2.3 Catenane-type molecular machines driven by acid-base stimuli
3 The applications of acid-base driven molecular machines
3.1 Supramolecular gel
3.2 Treatment of paraquat poisoning and supramolecular vesicles
3.3 Supramolecular catalysis
3.4 Supramolecular nanovalve
3.5 Supramolecular polymer
4 Conclusion and outlook

Supramolecular gels based on hierarchically self-assembly of small organic molecules through non-covalent interactions attract more and more attention because of the potential applications. Expected design of gelators that could directly self-assembly into fiber network instead of serendipity is challenging for both molecular recognition and supramolecular self-assembly. Pentacyclic triterpenoids with unique chiral skeleton structures are very important active biomolecules as natural products. They have much medicinal value because of their biological activities such as liver-protecting,anti-hyperlipidemia, anti-tumor, anti-virus and anti-inflammatory. Due to the characteristics of rigid chiral skeleton and multiple reaction sites, the aggregation and self-assembly properties of pentacyclic triterpenoids have attracted more and more attention. In this review, the aggregation property of pentacyclic triterpenoids without any modification in different solvents and supramolecular gels formed by functional molecules based on derivatives of triterpenoids are described in detail. In addition, the potential applications of the gels based on pentacyclic triterpenoids are also represented. Imitating and modifying these natural products used as building blocks in self-assembling architectures can not only minimize the tedious synthetic work of gelators and introduce ready units for supramolecular gels, but also help to elaborate the interactions between biomolecules and make use of natural products to create new materials.

Contents
1 Introduction
2 Supramolecular gels based on pentacyclic triterpenoids without modification
2.1 Supramolecular gels based on lupane-triterpenoid
2.2 Supramolecular gels based on oleanane-triterpenoid
3 Supramolecular gels based on pentacyclic triterpenoid derivatives
3.1 Gelators of pentacyclic triterpenoid derivatives start from carboxyl
3.2 Gelators of pentacyclic triterpenoid derivatives start from hydroxyl
4 Conclusion and outlook

Dicationic ionic liquids (DILs) are a fascinating class of novel ionic liquids consisting of two cationic moieties combined with a spacer and two anionic moieties. DILs have recently received more and more attention because of their unique and interesting advantages compared with traditional monocationic ionic liquids while maintaining the same desirable solvation properties, such as higher thermal and chemical stability, excellent structural tunability, superior heat capacity and so on. Given the tunability of DILs, they are more suitable for use in a plethora of science and engineering applications, such as high-temperature organic synthesis, chromatography stationary phases, stable quasi-solid-state dye-sensitized solar cell, separation process, and novel high-temperature lubricant. The recent research progresses of DILs are systematicly reviewed in this paper. General methods for synthesis of various types of DILs, including symmertrical and asymmertrical DILs, are summarized. Properties of DILs in terms of melting point, density, viscosity, heat capacity, thermal stability, surface and interfacial properties, toxicity and biodegradability are respectively described in detail. The structures and molecular dynamics of DILs are introduced in brief. The applications of DILs in organic synthesis, material preparation and electrochemical field are briefly overviewed. In addition, the application prospect and development trend of DILs are finally prospected.

Contents
1 Introduction
2 Synthesis of DILs
2.1 Synthesis of symmertrical DILs
2.2 Synthesis of asymmertrical DILs
3 Properties of DILs
3.1 Physicochemical properties
3.2 Surface & interfacial properties
3.3 Toxicity and biodegradability
4 Structures and molecular dynamics of DILs
4.1 Structures
4.2 Molecular dynamics
5 Applications of DILs
5.1 Organic synthesis
5.2 Material preparation
5.3 Electrochemical field
6 Conclusion

Anodic TiO₂ nanotubes fabricated by anodization have a wide range of applications in a variety of fields because of their unique structure and excellent performance. Also, the formation mechanisms of anodic TiO₂ nanotubes have gradually become a hotspot of research in the field of the porous anodic oxides. A series of papers about formation mechanisms of anodic TiO₂ nanotubes have been published in many famous journals in recent years. The present article has reviewed the latest progress and significance of the research on formation mechanisms of anodic TiO₂ nanotubes in the contrast of two kinds of anodic oxide films. Here, we firstly introduce the anodizing process of Ti, and then analyze the difference and connections of two kinds of anodic oxide films,that are compact anodic oxide film and porous anodic oxide film. Then we introduce the growth process of TiO₂ nanotubes, focusing on different kinds of formation mechanisms of TiO₂ nanotubes. The results show that there are a lot of limitations for the traditional field-assisted dissolution theory in explaining the growth process and the porous structure of TiO₂ nanotubes, but the combination of viscous flow model and growth model of two currents can give a comprehensive explanation to the growth process of TiO₂ nanotubes. However, the validity of oxygen evolution resulting from electronic current has yet to be further investigation.

Contents
1 Introduction
2 Electrochemical anodization of Ti
2.1 Compact anodic titanium oxide films
2.2 Porous anodic titanium oxide films or TiO₂ nanotubes
3 Formation mechanism and growth process of TiO₂ nanotubes
3.1 Field-assisted dissolution theory and growth process of TiO₂ nanotubes
3.2 Viscous flow model
3.3 Growth model of two currents and growth process of TiO₂ nanotubes
4 Conclusion

Chiral phenomena are ubiquitous in nature from macroscopic to microscopic, including the high chirality preference of small biomolecules, e.g. L-amino and D -saccharide, special steric conformations of bio-macromolecules induced by it, e.g. DNA, as well as chirality-triggered biological and physiological processes. The introduction of molecule chirality onto the surface of gold nanoclusters lead to the generation of chiral gold nanoclusters, which provides a new platform for controlling chirality signal transmission from molecular level to nanoscale level. As one of most intensively investigated materials with unique properties of both chiral-molecule and gold nanoclusters, chiral gold nanoclusters have application in molecular detection, chiral catalysts, chiral recognition and many other areas. This critical review gives a brief introduction to the recent advances in this field. We start from the preparation of chiral gold nanoclusters, and further characterize their structures to find out key factors governing the chiroptical properties, further introduce some hot applications and finally discuss the future developments and challenges of chiral gold nanoclusters.

Contents
1 Introduction
2 Synthesis and characterization of gold nanoclusters
2.1 Synthesis of chiral gold nanoclusters
2.2 Purification and isolation
2.3 Characterization of chiral gold nanoclusters
3 Properties of chiral gold nanoclusters
3.1 Special optical activity
3.2 The origin of chirality
4 Application of chiral gold nanoclusters
4.1 Chiral catalysis
4.2 Chiral recognition
4.3 Potential application
5 Conclusion and outlook

Polymer derived silicoboron carbonitride (SiBCN) ceramics possess such excellent properties as high temperature stability, oxidation resistance, creep resistance and special electrical properties. They have been fabricated as ceramic fibers, composites, porous ceramics, coatings, microdevices, and become alternative materials for potential applications in the fields of aerospace, energy, microelectronics. In recent years, researchers have made great progresses in developing new methods of precursor synthesis. The characterizations in microstructures and high temperature properties of SiBCN ceramics have been carried out. Possible applications in high temperature sensors, oxygen resistance coatings of carbon nanotubes/carbon nanofibers (CNTs/CNFs), and sintering additives have also been sought. The preparation routes of polymer derived SiBCN ceramics (including synthesis, pyrolysis and processing of precursors), the microstructures, basic properties and high temperature properties of SiBCN ceramics are reviewed. Accordingly, major problems are summarized and future research trends are highlighted.

Contents
1 Introduction
2 Synthesis routes of polymer derived SiBCN ceramics
2.1 Preparation of precursors
2.2 Pyrolysis and processing of precursors
3 Microstructures and basic properties of SiBCN ceramics
4 High temperature properties of SiBCN ceramics
4.1 Thermal stability and oxidation resistance
4.2 Creep resistance
4.3 Electrical properties
5 Conclusion and outlook

As a kind of important organic synthesis intermediates, terminal arylacetylenes are widely used in many fields and concerned by many researchers. This review mainly describes the synthesis of terminal arylacetylenes by using vinyl bromides, aryl halideas, aromatic aldehyde as the starting materials in recent ten years. The applications and mechanisms of some reactions are also described. The further work needed to do and the development trends in this field are proposed.

Contents
1 Introduction
2 Synthesis of terminal arylacetylenes
2.1 From vinyl halides
2.2 From aryl halides
2.3 From aromatic aldehydes
2.4 Other methods
3 Conclusion

Poly(N-vinylcaprolactam) (PNVCL) is a thermoresponsive polymer with a lower critical solution temperature (LCST) close to body temperature. The hydrolysis of PNVCL does not produce toxic amine compounds. And PNVCL derives from an inexpensive commercially available monomer, N-vinyl caprolactam (NVCL). These make PNVCL and PNVCL-based polymers highly useful for biomedical applications and open perspectives for industrialization. But NVCL is a typical non-conjugated monomer and it can only be polymerized via radical polymerization, thus living/controlled free radical polymerization of NVCL is the only possible means to obtain the desired well-defined polymeric structure. This review summarizes recent advances regarding the living/controlled radical polymerization of N-vinylcaprolactam, including atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, and cobalt-mediated radical polymerization (CMRP). The influence of ligands, solvents, and initiators on ATRP of NVCL is introduced. RAFT polymerizations of NVCL are discussed by xanthate-mediated, dithiocarbamate-mediated, dithioester-mediated and trithiocarbonate-mediated controlled radical polymerization. We also highlight recent results in influence of the sequence of monomer addition on synthesis of NVCL-based block copolymers and the controlled synthesis of PNVCL-containing topological macromolecules, such as linear-dendritic block copolymers, star polymers, hyperbranched block copolymers and cyclic polymers obtained by controlled radical polymerization of NVCL. The future directions in living/controlled free radical polymerization of N-vinylcaprolactam are also discussed.

Contents
1 Introduction
2 ATRP of NVCL
2.1 Influence of ligands
2.2 Influence of solvents
2.3 Influence of initiators
3 RAFT polymerization of NVCL
3.1 Xanthate-mediated RAFT polymerization
3.2 Dithiocarbamate-mediated RAFT polymerization
3.3 Dithioester-mediated RAFT polymerization
3.4 Trithiocarbonate-mediated RAFT polymerization
4 CMRP of NVCL
5 Influence of the sequence of monomer addition on synthesis of NVCL-based block copolymers
6 Combination of two different living/controlled free radical polymerization techniques
7 The controlled synthesis of PNVCL-containing topological macromolecules
8 Conclusion

As an ideal electrode material with excellent physical and chemical properties, graphene has been widely concerned in electrocatalysis and electroanalytical applications. It may be limited by the great in the electrochemical application areas due to its irreversible agglomeration. However, it is well realized that graphene oxide can provide a new way to separate graphene sheets for the reason of its good hydrophilic characteristic and also that the preparation of graphene oxide usually is simple and easy. But the electron transmission capacity of the modified interface based on graphene oxide would be further decreased due to its oxygen-containing groups, which are not benefited for the eletrocatalysis and electrochemical sensors with high sensitivity. Additionally, oxygen-containing groups of graphene oxide can be reduced by using some reduction methods so as to restore a more perfect graphene structure with planar conjugated, which will further improve the conductivity and adjust the band gap of graphene oxide. Therefore the electro-catalytic properties of the resulting materials can be adapted by using such reduction methods. Electrochemical sensors based on electrochemical reduced graphene oxide (ERGO) have been widely applied in all kinds of electrcatalytic and electrochemical sensor research fields due to its unique characteristic and advantages. In this paper, the recent progress of electrochemical sensor based on ERGO materials are briefly reviewed, including the characteristics, preparation principle and methods, classification of such electrochemical sensing platform and, also its applications as electrochemical sensing in the field of environmental pollutants, the food and drug, DNA and biological analysis. In addition, the future development and application prospect of this kind of ERGO based electrochemical sensors were further discussed.

Contents
1 Introduction
2 Preparation of ERGO modified electrodes
2.1 Indirect electrochemically reduced method
2.2 Direct electrochemically reduced method
3 Classification of ERGO modified electrodes
3.1 Intrinsical ERGO modified electrodes
3.2 The composite modified electrodes based on inorganic nanoparticles and ERGO
3.3 The composite modified electrodes based on organic compounds and ERGO
3.4 The composite modified electrodes based on inorganic-organic and ERGO
4 Electrocatalytic and electrochemical applications of ERGO modified electrodes
4.1 Electrochemical analysis of small molecules
4.2 Electrochemical analysis of molecules containing aromatic structure
4.3 Electrochemical analysis of biological molecules (protein and DNA)
5 Conclusion and outlook

Nano-sized exosomes originated from cells with a diameter of 40~100 nm can carry and transport "cargo" in cell-to-cell communication. They are important mediators of intercellular communication and regulators of the cellular niche. Their altered characteristics in many diseases suggest their important roles in diseases diagnosis and therapy, thus prompting the idea of using exosomes as drug delivery vehicles. As naturally occurring endogenous carriers of drugs, exosomes have unique advantages such as limited immunogenicity, great stability in blood, high delivery efficiency, targeting ability, and the improvement of enhanced permeability and retention effect (EPR). So far, genetic drugs, anticancer drugs, anti-inflammatory drugs and etc. have been successfully delivered by exosomes. In these cases, exosomes contribute to improving transfection efficiency of gene and reducing their side effects, as well as protecting therapeutic drugs from clearance by human bodies. This review covers the latest developments in the field of exosome-based drug delivery systems with regard to "cargo" species. Key components of exosome-based drug delivery system, such as the sources and purification methods of exosomes, choice of therapeutic cargo, loading methods, and administration routes are briefly discussed. At last, the challenges of exosomes as drug carriers in clinical practice are raised and the possible solutions are proposed.

Contents
1 Exosomes and their biofunction
2 Exosomes as drug carriers
2.1 Key components of exosomes as drug carriers
2.2 Exosomes as genetic drug carriers
2.3 Exosomes as anticancer drug carriers
2.4 Others
3 Conclusion and outlook

Lignocellulosic biomass is an important renewable resource, and has potential application in high quality biofuels to substitute fossil energy and reduce green house gas emission. Among those high quality biofuels, oxygen-contained 2,5-dimethyl furan (DMF) and C₅/C₆ alkanes show particular interests because these two kinds fuels could be produced from biomass via 5-hydroxymethyl furfural (HMF) intermediate. DMF is an ideal replacement and/or dopant for the presently used gasoline by enhancing combustion efficiency and reducing contaminant emission because of its higher energy density, higher octane number and higher boiling point. On the other hand, C₅/C₆ alkanes are the important gasoline components for adjusting the octane number and volatile properties. In this paper, combining our studies, we systematically summarize the status-of-the-art technologies for HMF synthesis from cellulose, and DMF and C₅/C₆ alkanes production by selective and complete hydrodeoxygenation of HMF respectively, depended on reaction medium, catalyst and pathway. The reaction mediums include water, ionic liquid, polar aprotic organic solvent and water contained biphasic solvent; and catalysts include inorganic acid, metal salt, solid acid and supported catalyst. Finally, the future of biomass derived DMF and C₅/C₆ alkanes production is remarked and prospected.

Contents
1 Introduction
2 HMF from cellulose
2.1 Mechanism
2.2 Reaction medium
2.3 Catalysic system
2.4 Side reaction
3 DMF from HMF through selective hydrogenolysis
3.1 Mechanism
3.2 Reaction medium
3.3 Catalysic system
4 C₅/C₆ alkanes from cellulose
4.1 Pathway of alkanes
4.2 Catalysic system
5 Conclusion and outlook

This article deals with the recent research and development on catalytic oxidehydration of glycerol into acrylic acid in a single reactor. The biorenewable glycerol as a platform chemical for the production of acrylic acid is introduced. The reaction parameters such as temperature, contact time, partial pressure of oxygen and glycerol concentration in the gas-solid systems and the liquid-solid systems are examined. The catalytic performances of oxide composites and molecular sieve-supported catalysts in a single-bed system and a double-bed gas-solid system are discussed. The catalysts include V-P, Fe-P, W-V, Mo-V, CsPW-Nb, VMo-SiC oxide composites, V₂O₅/BEA and V₂O₅/MFI. The postulated reaction mechanisms and probable side reactions in the gas-solid system are presented, followed by the discussion on the issues of catalyst deactivation and regeneration. Then the catalytic characteristics of Cu/SiO₂-MnO₂ and POM/Al₂O₃ catalysts and the reaction mechanism in the liquid-solid system are remarked. The problems and the prospects in the selection of catalytic system, the improvement of catalysts and the elimination of coking of catalysts are commented.

Contents
1 Introduction
2 Gas-solid catalytic reactions
2.1 Gas-solid catalytic reactions in a single-bed reactor
2.2 Gas-solid catalytic reactions in a double-bed reactor
2.3 Mechanism of gas-solid catalytic reactions
2.4 Deactivation and regeneration of catalysts
3 Liquid-solid catalytic reactions
3.1 Reaction conditions of liquid-solid catalytic reactions
3.2 Catalysts of liquid-solid catalytic reactions
3.3 Mechanism of liquid-solid catalytic reactions
4 Conclusion

Metastable intermolecular composite (MIC) Al/Bi₂O₃ has good features of high combustion efficiency, fast energy releasing rate, high pressure pulse, good safety performance and being environment-friendly. It shows good application prospects in pyrotechnics, explosives and propellants, etc. In this review, reaction mechanisms and models, preparation and applications of the metastable intermolecular composite Al/Bi₂O₃ are summarized. First, various theories and models which were used to explain the reaction mechanism of thermites are introduced and compared. The models of the CJ(Chapman-Jouguet) detonation and thermal equilibrium which could interpret and simulate output pressure of Al/Bi₂O₃ reasonably are discussed in detail. Second, the preparing methods of Bi₂O₃ and Al/Bi₂O₃ are summarized. By using different preparing processes, the morphologies, microstructures and combustion performances of composites could be regulated. Meanwhile, the effects of reactants particle size and various additives in preparing Al/Bi₂O₃ on its combustion performances are analyzed. Furthermore, a brief introduction of the application research is also presented. Finally, we proposed prospects about the metastable intermolecular composite Al/Bi₂O₃.

Contents
1 Introduction
2 Thermite reaction mechanism
2.1 Ignition mechanism
2.2 Pressure generation model
3 Preparation methods
3.1 Preparation of nano Bi₂O₃
3.2 Preparation of nano Al/Bi₂O₃
4 Performance tuning of Al/Bi₂O₃
4.1 Particle size of material
4.2 Additive
5 Applications of Al/Bi₂O₃
5.1 Initiating explosives
5.2 Miniature initiating explosive devices
5.3 Propellants
6 Conclusion and outlook