Hydrogen energy is regarded as the ideal energy to resolve fossil fuels deficiency and environmental deterioration, as well as to accelerate the transition to green energy, due to abundant source, non-polluting, high in energy, and rich applications. To achieve industrial utilization of green hydrogen, three obstacles need to be addressed: long-term storage, convenient transportation and reasonable cost. Low-security and high-cost of hydrogen in storage and transportation can be resolved by the novel strategy of employing ammonia as a hydrogen carrier, which can exploit potential industrial applications. Researches are focused on the high-efficiency, stable and economical catalysts for ammonia reforming in the hydrogen-ammonia integration technology route. Taking into account the practical application, choosing well-matched reactor systems is another method to optimize general catalytic performance.In order to aid readers in comprehending the concepts and conclusions presented in this study, the catalyst characteristics, reaction mechanism, and reaction system of ammonia decomposition are examined. From the standpoint of the catalytic mechanism, the research describes the mutual coupling interactions of the four nanoeffects of size, confinement, defects, and metal-support interactions on the effective creation and long-lasting retention of catalytic reaction sites, respectively. Lastly, it examines the areas that can be further investigated in the future, both theoretically and experimentally, as well as the unresolved issues with ammonia breakdown catalysts’ activity, stability, and dispersion.

Herein, the influence of support type and properties on the catalytic activity and selectivity of Ag-based NH3-SCO catalyst was studied through the evaluation of NH3-SCO performance, the physicochemical characterization of H-2-TPR, NH3-TPD, N-2 isothermal adsorption-desorption, XPR and XPS, and the mechanism study of H-1 MAS NMR, In-situ DRIFTS and DFT calculations. Ag/nano-TiO2, Ag/Al2O3, and Ag/MnO2 all showed better NH3-SCO activity because of more abundant Br & oslash;nsted and Lewis acid sites of Al2O3 and TiO2 and more actual Ag loading amount due to the larger specific surface area and suitable surface chemistry. The N-2 selectivity of Ag/nano-TiO2 is significantly better, which may be due to the highly dispersed Ag species and the abundant Br & oslash;nsted acid sites with higher N-2 selectivity. The mechanism study showed that the terminal hydroxyl was the preferred consumption target of Ag species, and this consumption promoted the effective dispersion and stable anchoring of Ag on the TiO2 surface.

Bi and Cu co-modified g-C3N4 catalysts were prepared by a solvothermal synthesis method, which have excellent CO2 photothermal catalytic reduction activity.

As zero-carbon artificial ammonia synthesis technologies for nitrogen fixation, eNRR (electrocatalytic nitrogen reduction reaction) and pNRR (photocatalytic nitrogen reduction reaction) are receiving more and more attention, in which NRR catalysts play a crucial role with significant potential. Herein, The NRR mechanism including nitrogen adsorption, activation, electron migration, and hydrogenation, eNRR & pNRR experiment system, and the basic properties, structure-performance relationship and advanced improvement design of NRR catalysts are reviewed. Metal-based catalysts including Fe, Mo, Bi, Ti, Ru, Au, Ag, Ce, Zn, Sn and so on, have an advantage in nitrogen adsorption, nitrogen activation and ammonia selectivity. In addition to being catalyst support, non-metallic materials can also have certain NRR activity, such as g-C3N4 and graphene, especially with vacancy design and modification. Besides, the photoelectric and catalytic performance can be further improved by synthesize composite catalysts to produce heterojunction structure. This review aims to assist academia to understand the research progress of NRR technology and catalyst and provide ideas for innovating more promising and high-performance NRR catalysts.

With the increasing global warming, the control of nitrous oxide (N2O) emissions in various fields has become urgent. Direct catalytic decomposition is currently the most widely used technology to reduce N2O emissions from the nitric acid industry. Selective catalytic reduction (SCR), which can utilize unburned NH3 from engine exhaust as a reductant, is the most promising technology for reducing N2O emissions from ammonia-fueled engines. Increasing demands on the operating temperature window, O2/H2O/NO resistance, and hydrothermal stability of catalysts have stimulated the development of novel catalytic N2O removal catalysts. This review first summarizes the N2O generation mechanism, comprehensive N2O catalytic removal reaction mechanism and O2/H2O/NO inhibition mechanism, and then provides a comprehensive overview of the related catalysts, including Ru- and Rh-based precious metal catalysts, Cu- and Co-based non-precious metal catalysts, and Fe- and Cu-based molecular sieve catalysts, focusing on direct catalytic decomposition of N2O and N2O-SCR. Effective strategies for various catalysts to improve the acidity, redox cycling, and toxicity resistance of the catalysts through modification, creation of novel nanostructures, and exposure of specific crystalline surfaces are summarized, and the challenges and opportunities they face are presented. In addition, this paper summarizes some other methods for catalytic removal of N2O and develops a detailed description for the synergistic removal of N2O and NOx. Finally, this review provides some suggestions for future research directions. It is hoped that this review will provide a theoretical basis for the optimal preparation of catalysts to bridge the gap between catalyst performance and practical needs, and help to realize the commercial application of efficient catalysts in the near future.

The survival and sustainable development of humanity are gravely threatened by climate change, which has recently been elevated to the status of one of the greatest threats to humanity's survival and security on a worldwide scale. In response to global climate change, how to obtain renewable and clean fuels is an important challenge for the sustainable development of human society. In order to reach the carbon peak and attain carbon neutrality, using CO2 as a resource has become a crucial aim for human civilization. Converting CO2 into chemical products with higher added value, that is, CO2 resource utilization technology can not only achieve CO2 emission reduction but also have certain economic benefits. The technologies of CO2 resource utilization primarily include photocatalytic reduction, electrocatalytic reduction, thermal catalytic reduction, and relay catalysis. This paper mainly summarizes the mechanism of CO2 catalytic conversion technologies and the research status of related catalysts, and summarizes and discusses prospects for the development of the CO2 catalytic reduction system (catalyst modification, product selectivity improvement, etc.). The ideas and guidance are provided for the development of efficient and stable CO2 reduction catalysts and the application of CO2 catalytic reduction technology in the areas of environment and energy.

NH3-SCR technology is a highly efficient denitrification technology that is widely used in the purification of diesel exhaust and coal-fired flue gas from thermal power plants. Molecular sieve catalysts have been extensively investigated for their high activity and selectivity. In this review, the preparation, structure, active sites and some resistances of Cu -based molecular sieve catalysts, Fe -based molecular sieve catalysts and composite metal molecular sieve catalysts are systematically investigated for relevant elaboration. In addition, the NH3-SCR reaction mechanism over the catalysts is also explained. With the increasingly stringent requirements of NOx emission, we need to develop more efficient catalysts. This paper provides a summary of the hydrothermal aging stability and the inorganic element (S / P / Alkali and alkaline earth metal) poisoning mechanisms as well as the influence of the preparation process in the molecular sieve catalysts, and we hope this review contributes to the development of molecular sieve catalysts.

As a promising future energy material, g-C3N4 as a CO2 photo-thermal-reduction catalyst can effectively convert CO2 to renewable fuel, but the low yield and low product selectivity significantly limit its further development and application. Herein, Ag and Bi2MoO6 were loaded separately or together on g-C3N4 catalysts by photo-deposition and solvothermal synthesis methods, wherein the conversion efficiency of the g-C3N4 catalyst co-loaded with 0.5% Ag and 10% Bi2MoO6 was the highest (CO yield = 50.77 mu mol g(-1) h(-1), CO selectivity = 96.98%). Characterization shows that the co-loading of Ag and Bi2MoO6 reduces the band gap of g-C3N4, improves the light absorption performance, and promotes the photoelectron transfer and CO2 adsorption, which may be attributed to the LSPR of Ag and the Z-scheme heterojunction between g-C3N4 and Bi2MoO6. The results of in situ DRIFTS and DFT calculations are consistent with the above conclusion and show that Ag loading effectively reduces the energy barrier of each intermediate state. This thesis aims to provide data support and theoretical guidance for optimal design of g-C3N4 catalysts.

SCR (Selective Catalytic Reduction) catalysts are used in a variety of industrial applications to reduce nitrogen oxide (NOx) emissions from exhaust gases. SCR catalysts can be poisoned by contaminants in the exhaust gas, such as sulfur, phosphorus, and alkali metals. These poisoning leads to deactivation of catalysts and thus need to be avoided. The objective of this review is to provide a comprehensive and systematic overview of the mechanisms of poisoning and the research on resistance of various metal oxide catalysts, including vanadium-based, cerium-based, copper-based, manganese-based, and iron-based catalysts, as well as various zeolite catalysts. The discussion will cover the catalysts' resistance against hydrothermal aging, sulfur poisoning, phosphorus poisoning, alkali metal poisoning, alkaline earth metal poisoning, and heavy metal poisoning. Furthermore, potential approaches and strategies for enhancing catalyst resistance in the future will also be examined. The article serves as a valuable resource for researchers and practitioners working on SCR technology and emissions control, providing insights into the mechanisms of catalyst poisoning and strategies for improving catalyst resistance.

The selective catalytic oxidation of ammonia is considered one of the most effective methods for removing ammonia from industrial waste and vehicle exhaust gas. In this reaction, there are significant differences in the performance of different catalysts. To adapt to the complex environment of the post-processing stage, a catalyst with high low-temperature activity, high selectivity, high anti-poisoning ability, and high durability is urgently needed. The main purpose of this review is to introduce the highly active catalysts currently being studied in the selective catalytic oxidation reaction of ammonia and to introduce their ammonia conversion rate, nitrogen selectivity, durability, resistance to hydrothermal aging, and sulfur resistance. At the same time, the effects of reaction conditions, active substance loading, preparation methods, and calcination temperature on catalyst performance are also introduced. The article will first introduce the possible mechanisms of the selective catalytic oxidation reaction of ammonia and evaluate them, and then classify the catalysts into noble metal based catalysts, transition metal oxide catalysts, and bifunctional catalysts based on their performance characteristics. In chapter “3. Noble metal based catalysts”, it is mainly divided into silver-based catalysts, platinum-based catalysts, palladium-based catalysts, ruthenium-based catalysts, and iridium-based catalysts; In chapter “4. Transition metal oxide catalysts”, it is mainly divided into copper-based catalysts, iron-based catalysts, and composite metal oxide based catalysts; In chapter “5. Bifunctional catalysts”, the main focus is on catalysts composed of platinum-based or silver-based catalysts combined with copper-based or iron-based catalysts, which is currently the main research direction of bifunctional catalysts. At the same time, an evaluation and outlook will be conducted on the current research status of all types of catalysts. This article has important reference value for researchers studying ammonia emission control and provides feasible research directions for future researchers and practitioners.

In recent years, climate change has increasingly become one of the major challenges facing mankind today, seriously threatening the survival and sustainable development of mankind. Dramatically increasing carbon dioxide concentrations are thought to cause a severe greenhouse effect, leading to severe and sustained global warming, associated climate instability and unwelcome natural disasters, melting glaciers and extreme weather patterns. The treatment of flue gas from thermal power plants uses carbon capture, utilization, and storage (CCUS) technology, one of the most promising current methods to accomplish significant CO2 emission reduction. In order to implement the technological and financial system of CO2 capture, which is the key technology of CCUS technology and accounts for 70-80% of the overall cost of CCUS technology, it is crucial to create more effective adsorbents. Nowadays, with the development and application of various carbon dioxide capture materials, it is necessary to review and summarize carbon dioxide capture materials in time. In this paper, the main technologies of CO2 capture are reviewed, with emphasis on the latest research status of CO2 capture materials, such as amines, zeolites, alkali metals, as well as emerging MOFs and carbon nanomaterials. More and more research on CO2 capture materials has used a variety of improved methods, which have achieved high CO2 capture performance. For example, doping of layered double hydroxides (LDH) with metal atoms significantly increases the active site on the surface of the material, which has a significant impact on improving the CO2 capture capacity and performance stability of LDH. Although many carbon capture materials have been developed, high cost and low technology scale remain major obstacles to CO2 capture. Future research should focus on designing low-cost, high-availability carbon capture materials.

At present, in response to the call of the green and renewable energy industry, electrical energy storage systems have been vigorously developed and supported. Electrochemical energy storage systems are mostly comprised of energy storage batteries, which have outstanding advantages such as high energy density and high energy conversion efficiency. Among them, secondary batteries like lithium batteries, sodium batteries, and lead-acid batteries have received wide attention in recent years. Lithium-ion batteries (LIBs) have existed for a long time. However, due to limited lithium resources worldwide, uneven distribution, and worrying safety issues, the development of LIBs has been gradually hindered. Meanwhile, sodium-ion batteries (SIBs), whose working principle is similar to that of LIBs, have been gradually emphasized by researchers due to the advantages of abundant resources and low cost. Moreover, all-solid-state sodium batteries (ASSBs), which have higher energy density, simpler structure, and higher stability and safety, are also under rapid development. Thus, SIBs and ASSBs are both expected to play important roles in green and renewable energy storage applications. This Review focuses mainly on the detailed introduction of the constituent materials of SIBs and ASSBs, analyzing the development of cathode and anode materials and the solid-state electrolytes (SSEs) in the past five years. The advantages and development direction of each SSE suitable for ASSBs are listed and remarked, and the nonactive materials such as separators and collectors are briefly mentioned. Finally, a reasonable assessment and prospects of the different materials and preparation methods are put forward.

Herein, Ag/TiO2 NH3-SCO catalyst was prepared by impregnation-rotary evaporation method with different calcination temperature and Ag loading content. The results of performance evaluation and characterization showed that the 10 wt

With the introduction of the EU's "ban on combustion" proposal in 2035, the sale of new fossil fuel vehicles will soon be comprehensively prohibited. The use of e-fuels has become the best means for the survival and continuation of internal combustion engines, while also responding to the call for carbon neutrality. This review studies how the raw materials required for different e-fuels can be obtained through the assistance of renewable energy or various net-zero carbon emission routes, and elaborates on the synthesis methods, economics, and challenges faced by e-fuels such as e-methanol and e-ammonia. E-fuels have a wide range of market applications, including but not limited to road transportation, aviation, and shipping, and some transportation vehicles have already chosen e-fuels as their fuel. By summarizing the technoeconomic analysis of e-fuels, this review aims to provide referable methods and multiple options for the future large-scale production of e-fuels, as well as insights for the subsequent application and improvement of e-fuels.

Herein, Pt/TiO2 and Au/TiO2 catalysts were synthesized by photodeposition method, and CO2 photothermal reduction performance, physicochemical characterization, photochemical characterization and in situ mechanism experiments were performed on catalysts with different Pt and Au loading ratios. The results showed that the loading of Pt and Au can effectively enhance the optical absorption characteristics of TiO2, which is due to the strong metal-semiconductor interaction and the plasmon resonance effect on the surface of noble metal nanoparticles. PT-0.4 and AT-2 had a relatively stronger photochemical absorption and conversion ability. In addition, the load of Pt mainly enhances the selective conversion to CH4, while the load of Au mainly enhances the selective conversion to CO. However, Pt nanoparticles are prone to noble metal agglomeration, which reduces the catalytic activity, while Au nanoparticles are relatively stable. Mechanism study showed that PT-0.4 and AT-2 catalysts have similar intermediate species in the dark adsorption and light reaction stages, but PT-0.4 mainly achieves CH4 generation through intermediate species such as *CHO, while the key species of CO generation on the surface of AT-2 is mainly *COOH.

To mitigate the rising threat to global climate aroused by dramatically increasing anthropogenic CO2 emissions in recent years, the Paris Agreement sets a goal of limiting the rise in average global temperatures to 1.5 to 2 degrees C over preindustrial times. Traditional negative emissions technologies (NETs) are important approaches to reach that goal, but it is still not enough from a long-term perspective. Therefore, the research on direct air capture (DAC) is imperative now as a new promising approach. This paper first summarizes the different systems DAC can deal with, such as gas/solid, gas/liquid, and gas/polymer systems, and then illustrates the thermodynamic feasibilities of DAC under each condition. From a perspective of industrial practice, the review presents several hopeful chemical technologies from many aspects including capturing material, process flow, and techno-economic analysis, with contents allocated by the maturity of the technology. This review especially analyzes demonstration plants like Climeworks and explores experiences about how to transform early laboratory results based on unit operation into large-scale production. Finally, this review discusses the advantages and disadvantages of the technologies mentioned and provides some suggestions for future research and development.

With the energy transition looming, the search for carbon-free fuels is imperative. Hydrogen is an excellent alternative to fossil fuels, but there are significant challenges in transport and production. Ammonia is an excellent hydrogen carrier with 17.6 wt % hydrogen content and zero carbon, and the infrastructure for its production, storage, and transport is already well-established. Currently, ammonia decomposition for hydrogen only reacts at high temperatures; therefore, the challenge is to optimize highly active catalysts for ammonia decomposition at low temperatures. This review will start from the background of ammonia decomposition for hydrogen, thoroughly introduce the ammonia catalytic decomposition systems, mainly covering ruthenium-based, iron-based, cobalt-based, nickel-based, metal nitride, metal carbide, and new alkali metal amide-imide systems, analyze in detail the influence of different catalyst preparation methods, supports, promoters, and other methods on the catalytic activity, and discuss the general rules for optimizing the efficiency of catalysts. Moreover, the reaction kinetics of different catalysts, including reaction mechanisms, reaction-determining steps, and activation energies, are presented, and future prospects on ammonia decomposition catalysts are proposed.

Ammonia leakage emissions are an important environmental issue in the management of air pollutants. This paper summarizes the current development in the field of the selective catalytic oxidation of ammonia (NH3-SCO) in the past 20 years; briefly introduces the common catalyst preparation methods and carrier types; focuses on noble metal based catalyst systems with Ag, Pt, Ru, Pd, and other noble metals as the mainstay and transition metal based catalysts with Fe, Mn, V-Ce, and Cu monomer or their oxides as the mainstay and their modification methods; outlines the several reaction mechanisms common to different catalyst systems in the NH3-SCO reaction; and presents the reaction mechanism of NH3 and CO co-oxidation. The emergence of low-temperature, high activity, and high selectivity NH3-SCO catalysts requires attention to the graded dehydrogenation reaction of NH3, and therefore we strongly recommend the development of innovative catalysts with strong NH3 adsorption activation and O-2 activation capabilities.

In today's context of carbon-neutral carbon peaking and uneven distribution of global fossil energy, future-oriented artificial photosynthesis may become the key to solving the problem, and the realization of photothermal coupling catalytic one-step reduction of CO2 and H2O to renewable synthetic fuels is a more critical step in the selection and design of catalysts and the study of the reaction mechanism. Among them, TiO2 is widely used in the photothermal reduction of CO2 because of its excellent photothermal chemical properties. However, the photothermal catalytic mechanism of TiO2 is not clear at present, and there is a lack of effective modification to enhance the catalytic activity. In this study, TiO2 nanoribbon materials with an anatase phase were synthesized by hydrothermal modification of TiO2 carriers, and the doping of metal Bi was carried out by various methods on this basis. The performance and selectivity of the modified TiO2 catalysts were evaluated by photothermal catalytic reduction of CO2 and H2O, while the physicochemical properties and photochemistry were determined by XRD, Raman, BET, SEM, EDS mapping, TEM, XPS, UV-vis DRS, PL, TR-PL, CO2-TPD, and in situ DRFITS. The catalysts were analyzed by in situ characterization techniques to reveal the effects of carrier modification, semiconductor compounding, metal loading, and doping on the catalytic performance, physicochemical properties, and photothermal properties of the catalysts and then to explain the mechanism of CO2 catalytic reduction, which provides theoretical guidance and data support to improve the selection and design of catalysts.

The preparation, modification and reaction mechanism of four kinds of bismuth photocatalysts are reviewed, and their application and limitation are discussed.