The development of innovative catalysts for various electrochemical scenarios is crucial in satisfying the growing demands for sustainable energy and environmental conservation. Conductive metal-organic frameworks (c-MOFs) based on phthalocyanine complexes known as phthalocyanine-based c-MOFs, have shown promising potential in electrochemical energy conversion and environmental research. These c-MOFs represent a new category of layer-stacked porous MOFs with in-plane extended π-conjugation structure, which can enhance electrocatalytic activity by facilitating the mass diffusion of reactants and electron/charge transfer. The exceptional promising for a variety electrocatalytic reactions, such as water, oxygen, CO₂, and nitrogen conversion. In this work, we focus primarily on phthalocyanine-based c-MOFs rather than other types of c-MOFs, providing a comprehensive overview of their conductive mechanisms and main electrocatalytic reactions. We also cover recent progress in the utilization of phthalocyanine-based c-MOFs as heterogeneous catalysts in electrocatalysis. Furthermore, we explore the challenges related to the utilization of phthalocyanine-based c-MOFs in electrocatalysis. The state-of-the-art research and insights into the future perspectives of phthalocyanine-based c-MOFs as electrocatalysts are also presented and discussed. This work aim to guide the development of phthalocyanine-based c-MOF electrocatalysts with enhanced activity.

The selective hydrogenation of unsaturated aldehydes is an important process of fine chemical processing that is widely used in the fields of flavor, medicine and food production, agricultural product processing, and so on. However, the hydrogenation reactivity of current catalysts still needs to be improved and further modulation of catalyst structures is needed. Three design strategies for the selective hydrogenation catalysts are summarized in this paper, modifying the electronic properties of metal active sites, enhancing the synergistic effect between the metal active sites and the electrophilic sites, and utilizing the structural effect to change the adsorption strength and hydrogenation activity of C=O bond or C=C bond. The influences of hydrogen source types, reaction solvents, temperatures and hydrogen pressures on catalytic performance are also summarized. The density functional theory (DFT) calculation, the reaction kinetic model, and the structure-activity relationship of catalysts related to the selective hydrogenation of unsaturated aldehydes are summarized. In the final section, problems, and challenges in the selective hydrogenation of unsaturated aldehydes are discussed, and some feasible solutions are further proposed.

Compared with three-dimensional zeolites, two-dimensional layered zeolites have greater advantages in many fields, with larger surface area, shorter diffusion distance and more ductile structure. In recent years, the research on two-dimensional layered zeolites has become a new hotspot. Based on previous research and summary, this article summarizes the synthesis methods of two-dimensional zeolites in the past five years from two types of synthesis perspectives (bottom-up and top-down methods), with a focus on reviewing the progress of different synthesis methods for the same topology of zeolite. In addition, this article briefly describes the applications of two-dimensional zeolites in the fields of catalysis, adsorption, and separation and looks forward to the broad application prospects of two-dimensional zeolites so as to provide theoretical guidance and reference basis for the synthesis and application of two-dimensional zeolites.

With the background of rapid economic development, the green synthesis of high-value-added chemicals has attracted great interest. Ethers and Esters, the products of hydroxyl compound conversion, are important green chemical products. However, the harsh reaction conditions limit their application. Herein, we review the developments in the catalysis of phenols alkylation to ethers and alcohols oxidative esterification to esters. The modification strategy and catalytic mechanism of the catalytic systems are summarized. The heterogeneous catalytic system and its mechanisms have been mainly discussed. It is found that the acid-base synergistic catalysis and the synergistic effect between metal and support are favorable for the green synthesis of ethers and esters under mild reaction condition. Besides, the application of photocatalysis in oxidative esterification of alcohols is highlighted because the photocatalytic reaction is considered a promising green synthesis method. Finally, the research on the catalytic conversion of hydroxyl compounds are summarized and prospected, and we believe that the synthesis and modification of new catalysts and the exploration of catalytic mechanisms is still a promising research field.

Hydrogen peroxide (H₂O₂) is an important green oxidizing agent, but the main anthraquinone process for production thereof suffers high energy consumption and large safety risks. Artificial photosynthesis H₂O₂ from water and oxygen features safe, environmentally friendly and energy-saving characteristics and has gradually become a research focus. Covalent organic frameworks (COFs) have been widely used in the photocatalytic production of H₂O₂ for their high specific surface area, good photocatalytic performance and structural tunability. This review summarizes the recent research progress in the field of COFs photocatalytic production of H₂O₂, discussing the reaction mechanisms for the production of H₂O₂ through oxygen reduction, water oxidation, and dual-channel processes. It introduces methods to improve the photocatalytic production of H₂O₂ by regulating the optical bandgap, enhancing charge separation capability, and improving carrier mobility of COFs through structural design and functional group modification. These methods contribute to the design of efficient, stable, and sustainable COFs for photocatalytic production of H₂O₂.

Metal-organic framework compounds (MOF), also known as porous coordination polymers, are a new type of organic-inorganic hybrid porous materials which are self-assembled from organic ligands and metal ions, and are an important part of nanomaterials. Compared to other porous materials, MOFs have a large surface area, high porosity and adjustable structure and properties, making them have a good application prospect in heterogeneous catalysis. In this paper, the background of MOFs catalysis is briefly reviewed, followed by a review and prospect of the recent progress of MOFs in catalytic conversion reactions of organic molecules, in order to provide a reference for the design and development of organic reactions catalyzed by MOFs.

Among the many non-precious metal catalysts that have been reported so far, M-N-C catalysts based on transition metal-nitrogen-carbon structure are considered as the most promising candidates to replace Pt-based catalysts for oxygen reduction reaction. Compared with other M-N-C catalysts, Fe-N-C catalysts exhibit the highest ORR activity in acidic environments due to the suitable adsorption energy of oxygen-containing intermediates and thermodynamically favorable 4e pathway. However, the practical application of this catalyst is still limited by the challenge of insufficient stability under the high voltage and strong acidic conditions of PEMFC. Thus, the preparation of stable and efficient Fe-N-C catalysts still faces many challenges. In this review, we systematically summarize the common synthesis methods of Fe-N-C catalysts, including spatial confinement method and template-assisted strategy, outline the half-cell and single-cell test methods used to evaluate the catalyst stability, and analyze the reasons for the discrepancies between the two test results. In order to design highly stable catalysts, a clear knowledge and understanding of the degradation mechanism is required, so we describe four possible degradation mechanisms for Fe-N-C catalysts: demetallization, carbon oxidation, protonation, and microporous water flooding, subsequently we propose some specific strategies to enhance the stability of Fe-N-C catalysts. Finally, the future development direction of Fe-N-C catalysts is discussed in this review. It is hoped that the comprehensive and in-depth study of Fe-N-C catalysts will guide the design and development of highly stable Fe-N-C catalysts for the application of PEMFC.

Organic light-emitting diodes (OLEDs) have the advantages of self-luminous, high efficiency, light and thin structure, and can achieve diverse designs such as transparency and flexibility. They have broad application prospects in fields such as display and lighting. Triptycene is a stable, three-dimensional, and rigid structure formed by connecting three benzene rings through saturated carbon, and the conjugation between the three benzene rings is very small. Different substituents on the three benzene rings can also achieve very stable chirality. The triptycene group can provide an ideal rigid three-dimensional framework for the design of high-performance luminescent materials, in order to enhance the stability of luminescent materials, regulate intermolecular interactions (reduce concentration quenching while improving film formation), and maintain a stable chiral environment. In this paper, the research progress of incorporating triptycene group into electroluminescent electron transport layer and light-emitting layer material molecules is reviewed. The future of triptycene based electroluminescent materials is also prospected. By analyzing and summarizing the influence of triptycene group on material properties, its advantages are identified, so as to play a role in attracting more researchers to carry forward the advantages of triptycene in the field of new materials in the future.

Click chemistry won the Noble Prize in 2022 due to easy synthesis, high selectivity, single product, and no toxic side product. Click chemistry was originally designed as green chemistry to work in aqueous solutions or environmentally friendly organic solvents. However, due to the poor solubility of reactants, polar and toxic solvents are usually required to use. The solvent used violates the concept of green chemistry, as well as increases the cost. These issues hinder click chemistry to be a state-of-art green chemistry. One of the solutions to optimize click chemistry is to avoid using any solvent. Herein, ball-milled mechanochemistry does not limit reactants’ solubility and could avoid solvent use. Ball-milled mechanochemistry is a new kind of chemical reaction that is conducted in a ball mill, is induced by mechanical force, and needs no solvent or a minimal amount of solvent. As a new way of organic synthesis, ball-milled mechanochemistry could easily achieve the low-energy carbon-heteroatom bonds, which constitute the linkages in click chemistry. Therefore, it could integrate with click chemistry and achieves ball-milled click chemistry. In comparison to traditional solution click chemistry, ball-milled click chemistry avoids solvent use. Moreover, it is even superior in the ways that the reaction time is shortened, the reaction temperature is lowered, and the catalyst used is simplified. In this review, ball-milled click chemistry examples are reported as much as the authors can find, including CuAAc, Diels-Alder, amine and isothiocyanate reactions, amine thiol reactions, and nitroxide radical coupling reactions. To provide readers with a better ball-milled click chemistry manual, this paper also contains ball mill machine choice guidance, liquid-assisted grinding choice guidance, and factors impacting ball-milled click chemistry conversion, including catalyst choice, additive choice, ball choice, stoichiometry, and milling time.

As a kind of important biological macromolecules, proteins have been widely used in chemical and medical fields, such as biocatalysis, drug delivery, and molecular imaging due to their special three-dimensional spatial structure and high catalytic activity. However, there are a series of problems in the practical application of proteins. For example, proteins are easily inactivated in extreme environments. Protein drugs have strong immunogenicity in vivo, which leads to short half-life of drugs and causes adverse reactions in patients easily. Their low solubility in organic solvents limits their use in organic solvents. In order to solve the above problems, researchers have developed methods such as protein engineering and co-immobilization, but there are corresponding shortcomings. Polymer modification is one of the important methods, which can improve the properties of proteins from many aspects and expand the application of proteins. From this point of view, this review focuses on the latest research and classical literature on polymer-modified proteins, and introduces their ingenious modification methods to synthesize materials with excellent properties. The principle, practical application, existing problems and solutions of improving protein stability and activity, immunogenicity, solubility and self-assembly by polymer modification are summarized. On this basis, the challenges and possible development trends in the commercial and clinical translation of this strategy are analyzed.

Covalent organic frameworks (COFs) are porous organic materials with periodic two-dimensional or three-dimensional network structures consisting of two or more organic molecules connected by covalent bonds. COFs have attracted considerable interest in energy storage due to their beneficial properties, including low skeletal density, high surface area, high porosity, structural designability and functional modifiability. COFs offer unique advantages as positive electrode materials for metal ion batteries due to their rich redox active sites and open framework structure. However, their application in energy storage is limited by challenges such as poor conductivity, low energy density, limited number of available active sites, and blockage of ion transport channels. This article provides a comprehensive review of recent research on COFs as positive electrode materials for metal ion batteries, discussing their types, design strategies, and synthesis methods. Additionally, it presents an overview of the electrochemical energy storage mechanisms from the perspective of different active groups, and the applications of COFs in various metal ion batteries. Finally, it highlights the prospects and challenges of using COFs in energy storage.

High-density aviation fuels are a type of hydrocarbon which are synthesized to improve the flight performance of aerospace vehicles. They have the advantages of high density, high volumetric net heat of combustion value, and can effectively improve the flight performance of vehicles such as range, speed, load, etc. With the decrease of global fossil resources and the continuous deterioration of the ecological environment, the synthesis of high-density aviation fuels from biomass has become a research hotspot. In this review, the research progress in synthesis of multi-cyclic hydrocarbon high-density aviation fuels from platform molecules and derivatives in recent years is discussed. The common C-C bond coupling methods for constructing the multi-cyclic structure are introduced, including aldol condensation reaction, alkylation reaction, aldol-hydrodeoxygenation-alkylation reaction, Diels-Alder reaction, photoinduced 2+2 cycloaddition, rearrangement reaction. The new progress in synthesis of petroleum based high-density aviation fuels or multi-cyclic hydrocarbon mixed fuels from platform molecules is listed. The properties of a large number of multi-cyclic hydrocarbon high-density aviation fuels are summarized, and the influence of molecular structure and composition on fuel properties are discussed. Introduction of the appropriate substituent groups and synthesis of multi-component fuels are the main methods to improve the comprehensive properties of fuels. Synthesis of petroleum-based high-density fuels using platform molecules is another strategy to improve the properties of fuels. Finally, the development trend of synthesis of multi-cyclic hydrocarbon high-density aviation fuels using platform molecules from biomass is prospected.