Green synthesis of N-containing heterocycles has drawn increasing attention due to their significant applications in pharmaceuticals, dyes, and materials, while remains a great challenge. Herein, we propose a one-pot synthesis of N-containing heterocycles from bioethanol and amino alcohols via dehydrogenative dual-cross-condensation and secondary-cross-condensation by cascade catalysis. Isolated yields of 93% to pyrrole in reaction of bioethanol with 2-aminoethanol, 95% to N-ethyl-1,2,3,4-tetrahydroquinoline in reaction of bioethanol with 2-aminobenzyl alcohol, and 94% to N-ethyl piperidine in reaction of bioethanol with 3-aminopropanol have been achieved using a Ni catalyst supported Zr-containing layered double oxides without any additives. This work provides not only a green and sustainable method for production of the N-containing heterocycles but also a promising way for the sustainable use of bioethanol and even biomass industry.

Samarium (Sm) is one of the most important rare earth elements that have flexible entry to dual oxidation states (+3 and +2) under standard laboratory conditions, which has made it extremely valuable in chemical synthesis. Sm(II) reagents are widely used as versatile and stoichiometric reductants in organic synthesis. However, the use of a huge amount of metal salts and organic solvents causes cost and environmental issues, making Sm(II) reagents not potentially applicable to large-scale or industrial reactions. Therefore, the development of samarium-catalyzed reactions involving Sm(III)/Sm(II) redox cycling is of great importance. In this review, we summarize the state-of-the-art research on samarium redox catalysis. The key step of the redox cycle is the Sm(III)-to-Sm(II) reduction, which has thus far been enabled by various methods that will be outlined.

As a type of significant porous material, molecular sieves possess substantial application potential, particularly for catalysis and sustainability. However, the utilization of molecular sieves for photocatalytic synthesis has been hampered by the low charge transfer and poor photoresponse. Herein, we demonstrate that titanium silicalite (TS) zeolite serves as a versatile support integrated with TiO₂ and Pd for selective photocatalytic methane conversion into oxygenates. Comprehensive characterizations indicate that the pore structures of TS zeolite can enhance the adsorption and the localized concentration of reactants for subsequent reactions, while the Pd cocatalyst functions as the photogenerated hole acceptors under light illumination, forming Pd^δ+ species to facilitate the C-H bond cleavage of CH₄ molecules. As a result, the optimal Pd-TS@TiO₂ catalyst achieves a high production rate of 6.8 mmol g^-1 h^-1 with a selectivity of 96.5% for oxygenate products. This work provides valuable insights into reaction regulation through material design and paves the way for efficient methane conversion to high-value oxygenates.

Environmental pollution and energy scarcity are the big challenges for the development of contemporary society. The significant rise in global temperature further underscores the importance of adopting sustainable and clean energy sources for environmental purification. This review focuses on the photothermal catalytic oxidation technology, which combines the low energy consumption of photocatalysis with the high efficiency of thermocatalysis, demonstrating substantial potential in the removal of volatile organic compounds (VOCs). It systematically summarizes the research progress in the removal of VOCs by the photothermal catalytic methods over the past five years, and on the basis of the fundamental principles of photothermal catalysis, this review provides an in-depth analysis of the design principles of single-atom catalysts, reaction mechanisms, and their prospects in VOCs purification. The research emphasis includes the mechanisms of photothermic action, strategies for catalyst design, performance outcomes, and the limitations and challenges faced by the single-atom photothermal catalytic technology. It is envisioned that this review will guide the future development of single-atom photothermal catalysts and significantly advance such an emerging research field.

The electrochemical 2e^- oxygen reduction reaction (ORR) represents a green, cost-effective strategy towards hydrogen peroxide (H₂O₂) production other than a promising and more sustainable alternative to the currently anthraquinone-based technology. Light-weight hetero-doped carbon networks, particularly oxidized systems containing variables O-functionalities, have been deeply investigated as promising and selective metal-free electrocatalysts for the process. Following previous and positive outcomes from our team on the tailored surface engineering of complex C-nanocarbon networks with phenolic dangling groups as effective O-functionalities engaged for the molecular oxygen activation and its selective (2e^-) electroreduction, we propose hereafter a facile, scalable and highly reproducible one-pot protocol for the mild and controlled oxidation of multi-walled carbon nanotubes. The as-prepared materials have shown a phenolic enriched surface and a superior ability to foster the almost chemoselective 2e^- ORR process already under low overpotential values.

Renewable energy technologies are crucial for alleviating the energy crisis and pollution; electrocatalytic reactions such as oxygen reduction, hydrogen evolution, and oxygen evolution reactions are prospective energy conversion pathways. Although metal-based electrocatalysts are currently employed in electrochemical reactions, they encounter a series of issues with supply and price. Therefore, the development of new environmentally friendly, efficient, and low-cost electrochemical catalysts is imminent. Carbon-based materials such as amorphous carbons and nanostructured carbons have drawn extensive attention in electrocatalysis research due to their cost-effectiveness, environmental friendliness, and stability in acid and alkali media. In the initial stage, the heteroatoms embedded in the carbon skeleton (such as N, P, S, and B) were identified as active sites of carbon-based electrocatalysts. Subsequently, further investigations revealed that structural defects in carbon rings can disrupt the electronic conjugation system, which in turn affects the charge distribution and thereby enhances catalytic activity. Recently, our group has proposed a novel mechanism of defective carbon-based materials for electrochemical reactions, suggesting that the introduction of topological defects can boost electrocatalytic activity. Subsequently, extensive research has been carried out with direct evidence to prove different defects as active sites. Herein, we will emphasize the advancement of carbon-based electrocatalysts by a comprehensive understanding of catalyzing mechanisms. Then, the methodologies for controllably synthesizing doped carbons and carbons with defective structures will be summarized. Ultimately, we will outline the key challenges in designing intricate carbon active sites, particularly defect structures, provide insights into characterization techniques for investigating mechanisms, and importantly, look forward to future developments and opportunities.

The excessive emission of carbon dioxide (CO₂) has seriously threatened the global climate environment and human health; the efficient CO₂ reduction reaction (CO₂RR) as an effective method to reduce CO₂ emissions has become a hot spot in the current catalyst field. Metal-organic frameworks (MOFs) serve as ideal substrates for the preparation of single-atom catalysts (SACs) and dual-atom catalysts (DACs), attributed to their distinctive structure and superior pore characteristics. These catalysts address the issues of inadequate selectivity and activity in CO₂RR by facilitating efficient electron transfer at the atomic level. This review provides an overview of the design strategies for active sites in MOFs-based SACs and DACs, focusing on the synergy between single-atom and multi-atom configurations. It comprehensively summarizes the mechanisms of both photocatalytic and electrocatalytic CO₂RR and the relationship between active sites and catalytic efficiency. Additionally, the review provides an in-depth discussion of their applications in electrocatalysis and photocatalysis of CO₂RR, highlighting specific examples and advancements in these fields. Finally, the challenges of the future directions for active sites design and the development of improving catalytic activity in CO₂RR at industrial current density of MOFs-based SACs/DACs were looked forward.

Efficient visible-light-driven hydrogen production in the absence of noble metal is one of the major challenges for the application of photocatalytic water splitting. Herein, using cadmium sulfide (CdS) as a typical photocatalyst, we report on the synthesis of composite photocatalyst (CdS/MN) with CdS nanoparticles attached on two-dimensional (2D) layered molybdenum nitride (MN). The introduction of MN brings drastically enhanced photocatalytic activity of CdS by more than eight times, with an optimized hydrogen-production rate of ~58.4 mmol·h^-1·g^-1 and an apparent quantum yield of 62.5%. Characterization results indicate the charge transfer from CdS to MN for more efficient utilization of long-lived photogenerated electrons, with average lifetime of photogenerated charge carriers in CdS and CdS/MN estimated as 3.40 and 4.63 ns, respectively, and that MN could help to reduce the overpotential (280 mV) of hydrogen production reaction. Therefore, the excellent photocatalytic performance is attributed to the cocatalytic effect of 2D MN that helps to facilitate the charge separation and provides reactive sites for promoting hydrogen production reaction. This work provides an excellent example of efficient photocatalytic systems consisting of earth-abundant elements.

Recycling gold from used catalysts is significant for economic and environmental sustainability. Conventional methods, which heavily rely on the cyanide process, have posed significant environmental, health, and safety challenges. Herein, this study presents a novel approach for gold leaching from spent Au/metal oxide (Au/MO_x) catalysts coupled with an oxidative carbonylation reaction. This tandem process not only efficiently dissolves Au nanoparticles from used heterogeneous Au catalysts into soluble AuI^2- complex without using toxic cyanide, strong acids or oxidants, but also produces useful nitrogen-containing carbonyl compounds. Mechanistically, the leaching process is initiated by the in-situ generation of hydroiodic acid during the oxidative carbonylation reaction. This new approach has potential guide to the metal recovery and the design of stable heterogeneous catalysts.

Catalytic difunctionalizations of alkenes represent one of the most straightforward and efficient ways to build molecular complexity due to the simultaneous installation of two vicinal chemical bonds onto alkenes, providing profound chemical space for selective transformations in organic synthesis. Over the past decade, the merge of visible-light catalysis and earth-abundant-metal catalysis has taken advantage of green catalysis, thus evolving into an enabling platform for difunctionalization of alkenes. This dual catalytic mode facilitates the construction of multiple chemical bonds over the π-bond of alkenes in one step, providing a mild and straightforward method for the rapid construction of sp³-rich structures in a selective manner. In this review, we systematically summarized the progress of three-component cross-coupling reaction of olefins catalyzed by visible-light and first-row transition metal over the past decade. The combination of visible-light with different first-row transition metals, such as copper, nickel, chromium, titanium, manganese and iron, is discussed, along with the detailed reaction mechanisms. The scope of alkenes in this review includes alkenes, 1,3-dienes and 1,3-enynes. Moreover, the future directions and efforts in visible-light and earth-abundant-metal-catalyzed three-component reactions of alkenes are also discussed.

Amongst the most hazardous organic micropollutants (OMPs), β-naphthol, para-chloro-meta-xylenol, and bisphenol-A are highlighted due to their toxicity and persistent nature in aquatic environments. This work presents a series of cost-effective novel amine-functionalized porous aromatic frameworks (PAFs) for the adsorption of OMPs: PAF-82-NH₂, PAF-81-NH₂, and PAF-80-NH₂. PAF-82-NH₂ shows outstanding adsorption performance by exhibiting the highest Brunauer-Emmett-Teller surface area, polarity match with pollutants, and structural conjugation, with no loss in removal efficiency after five cycles of regeneration. The Langmuir adsorption capacity of PAF-82-NH₂ for three OMPs outstrips the most previously reported adsorbents: 461 mg·g^-1 for β-naphthol, 497 mg·g^-1 for para-chloro-meta-xylenol, and 763 mg·g^-1 for bisphenol-A. Despite having lower surface areas, amine-functionalized PAFs exhibit higher adsorption capacities than hydroxyl-functionalized PAFs (PAF-82,81,80). In comparison, PAF-1 (5,600 m²·g^-1) cannot even beat the adsorption capacity of PAF-81-NH₂, carrying the lowest surface area (564 m²·g^-1) among three amine-functionalized PAFs. This study reveals that the (-NH₂) group has a higher potential to enhance the adsorption capacity of OMPs than the (-OH) group. The specific surface area is not enough as a single factor preliminary without pore polarity. However, once polarity is established at pore channels, specific surface area, degree of conjugation, polarity, and size of pore channels work in a team fashion for efficient adsorption.

Asymmetric coordination structures in single-atom catalysts (SACs) represent a frontier in electrocatalysis, offering tunable electronic environments and enhanced catalytic performance beyond traditional symmetric M–N₄ motifs. This review first categorizes asymmetric SACs into four structural families: (1) single-metal asymmetric coordination, achieved by heteroatom substitution or axial ligand incorporation; (2) non-contact multi-metal sites, where adjacent but unbonded metal atoms synergize electronically; (3) directly bimetallic-bonded asymmetric coordination structures; and (4) bridged multi-metal constructs connected via non-metal linkers (e.g., O, N, S). Key synthetic strategies, including metal–organic framework confinement, defect engineering, dual-solvent loading, and macrocyclic precursor mediation, are examined in detail. Then we summarize applications in oxygen reduction reaction and CO₂ reduction reaction catalysis, and highlight how asymmetric coordination tunes intermediate adsorption energies, breaks scaling relations, and enables tandem catalysis to improve activity, selectivity, and stability. Advanced characterization techniques - aberration-corrected scanning transmission electron microscopy with electron energy loss spectroscopy, synchrotron X-ray absorption spectroscopy, and time-of-flight secondary ion mass spectrometry - are discussed for their roles in resolving atomic dispersion, coordination environment, oxidation states, and dynamic evolution under operando conditions. Finally, challenges and future directions are outlined, including precise low-temperature assembly of heteronuclear sites, scalability, long-term stability under harsh reaction conditions, selective pathway control, and the integration of operando analyses with theoretical modeling to guide rational catalyst design.

The robust O-formylation of alcohols using carbon dioxide to produce valuable alkyl formats is a green method for achieving carbon capture and utilization. However, developing a highly efficient heterogeneous catalyst with outstanding stability remains a significant challenge. Herein, we report a porous phenanthroline-based polymer-supported single-iridium-atom catalyst (Ir/POP-Phen) for the O-formylation of various alcohols using carbon dioxide and molecular hydrogen. This catalyst demonstrates superior catalytic activity and substrate compatibility compared to previous homogeneous and heterogeneous systems. In the synthesis of bulk methyl formate, the turnover number and turnover frequency reach up to 138,216 and 2,880 h^-1, respectively. Additionally, other types of alcohols are successfully converted into their corresponding alkyl formates. Notably, the Ir/POP-Phen catalyst exhibits high tolerance to water concentrations of up to 4,000 ppm during the O-formylation process and can be reused for four cycles without a significant decline in catalytic activity. This work offers insights into the rational design of heterogeneous catalysts for the O-formylation of alcohols.

This review summarizes the advances and applications of single-atom catalysts (SACs) in the selective catalytic reduction of NO by CO (CO-SCR). Various types of SACs are discussed, including conventional SACs, negatively charged SACs, dual-atom catalysts, singly dispersed bimetallic sites catalysts, single-atom alloy catalysts, and single-atom-cluster/nanoparticle catalysts. The unique properties of each type of catalyst and their catalytic performance in CO-SCR are explored. SACs enhance the adsorption and activation of NO through synergistic interactions with the support, thereby improving catalytic activity and optimizing the reaction pathway. Furthermore, tuning atomic structure, coordination environment, and metal-support interactions can further enhance the catalytic performance. Despite showing excellent catalytic activity under laboratory conditions, SACs still face challenges in industrial applications, such as catalyst stability, scalability and resistance to poisoning. Future research will focus on improving SAC stability, increasing the density of active sites, and enhancing resistance to deactivation. Combining advanced synthesis methods, large-scale production techniques, and in-depth structural characterization will be crucial for the industrial application of SACs in environmental and energy-related fields.

The growing demand for sustainable alternatives to fossil fuels has increased interest in biomass-derived chemicals, which play a vital role in the global transition toward renewable energy. Among these chemicals, γ-valerolactone (GVL) stands out as a promising intermediate for producing high-value chemicals, including bio-diesel. Zeolites, with their exceptional stability and catalytic activity, have demonstrated remarkable performance in GVL synthesis, making them highly suitable as heterogeneous catalysts for targeted biomass conversion. This review explores the mechanisms and methods employed in the preparation of these catalysts for converting various biomass feedstocks into GVL. Additionally, we discuss recent progress in zeolite-catalyzed GVL production from common biomass sources. Finally, we address the challenges and future prospects for developing more effective zeolite-based catalysts in GVL synthesis.

The catalytic reduction of nitro compounds to amines is crucial in the fine and bulk chemical industries. Single-atom catalysts (SACs), featuring high atomic utilization and unique unsaturated coordination structures, hold significant promise in this field and have garnered considerable attention in recent years. Despite notable advancements, their performance remains insufficient for industrial applications. Therefore, it is imperative to develop strategies to enhance their catalytic performance, particularly in terms of activity. This review comprehensively summarizes recent progress in the application of SACs for the hydrogenation of nitro compounds. Firstly, the synthesis and characterization of SACs are briefly discussed. Secondly, strategies to enhance the catalytic activity of SACs are highlighted, including the design of single-atom sites. This involves optimizing the metal center and its microenvironment to improve intrinsic activity, as well as increasing the loading and utilization efficiency of single-atom sites to enhance apparent activity. Key insights from the reviewed works are summarized. Third, the hydrogenation mechanism on some SACs is briefly discussed. Finally, the challenges and prospects of SAC applications in the hydrogenation of nitro compounds are discussed.

Glycerol is an important biomass platform molecule, produced as an abundant side-product in the biodiesel industry. The efficient conversion of glycerol through selective oxidation to value-added fine chemicals has been recognized as one of the most promising routes to meet the demand for escalating energy. However, glycerol oxidation usually involves the oxidation of the primary or secondary C–OH groups of glycerol, cascade oxidation of intermediates, and C–C oxidative cleavage of glycerol or its intermediates, resulting in multiple pathways and varied oxidative products. To achieve the selective conversion of glycerol to a single product is of great challenge. The development of efficient catalysts with precisely-designed active sites for the targeted activation of glycerol and the direct conversion to specific oxidative products is the key. In this review, we focus on the recent research advances of the selective oxidation of glycerol to the highly-desired C₃ value-added chemicals including dihydroxyacetone and glyceric acid over heterogeneous catalysts and the synergistic catalytic mechanism. The strategies for the targeted and efficient activation of glycerol at the primary or secondary position and the direct conversion of the primary or secondary C–OH and C–H bonds are emphasized. At the end of the article, future challenges and development strategies on the selective oxidation of glycerol are also discussed.

Single-atom catalysts (SACs) are widely used in carbon dioxide reduction reaction (CO₂RR) due to their distinctive electronic configuration and coordination environment. However, designing catalysts with porous structures that provide more active sites is a challenge in practice. Herein, we utilized the porous network structure of melamine foam (MF) and high temperature calcination to increase the number of nickel atoms to promote the formation of Ni-N_x active sites, resulting in nitrogen-coordinated nickel SACs with high catalytic activity. The X-ray photoelectron spectroscopy test demonstrates that the optimal calcination temperature of 900 °C can achieve a Ni-N_x site content of 9.47 at.%, which is significantly higher than that of other temperature conditions. This confirms that the calcination temperature has a decisive regulatory effect on the nitrogen-doped configuration and the formation of active sites. Furthermore, MF facilitated efficient electron transfer, resulting in improved catalytic performance. The Faradaic efficiency of CO (FE_CO) could reach 91% at -0.66 V vs. reversible hydrogen electrode. In situ Infrared Spectroscopy for real-time monitoring has demonstrated a linear relationship between Ni-N_x and the reaction intermediate ^*CO content, indicating that an elevated Ni-N_x content may facilitate the generation of more active sites and expedite the kinetic process of CO₂RR. The density functional theory calculations reveal that the Ni-N₂ coordination in the Ni-N_x surface is responsible for the superior catalytic activity of CO₂RR due to the moderate adsorption strength of ^*COOH with less negative U_L (-0.87 V). This experiment provides an innovative way to increase the active site content of SACs in CO₂RR.

Ammonia (NH₃) is widely utilized in agriculture to manufacture fertilizers and is an important feedstock in the pharmaceutical, metallurgical, and textile industries. Owing to its highly compressible nature, NH₃ is also regarded as an ideal carbon-free hydrogen carrier for the next-generation fuel cells. The Haber-Bosch process is currently the main method for NH₃ production but suffers from high energy consumption and intensive carbon emission. Recently, the plasma-electrochemical cascade pathway - plasma nitrogen fixation from air in tandem with electrocatalytic synthesis of NH₃ - has emerged as an alternative by the simplified process, low carbon emission, and high NH₃ yield. However, the research in this area has not been summarized timely. This review systematically summarizes the research progress of plasma-electrochemical cascade pathway for the first time. Through performance and energy consumption analysis, key issues that need to be addressed have been identified: improving the efficiency of plasma nitrogen fixation and NH₃ electrosynthesis. In response to these challenges, corresponding optimization strategies are provided in the end, pointing out the direction for the subsequent research on this emerging field.

The dehydrogenation of propane into propene is a crucial value-added process for producing raw chemicals from light hydrocarbons, such as shale gas. However, it faces challenges such as low propene yield and significant catalyst deactivation. In recent years, zeolite supported subnanometer or nanoparticles catalysts have attracted considerable attention and made remarkable progress due to their superior activity and exceptionally high thermal stability. In this review, we present an overview of design ideas of metal-containing zeolite catalysts used for propane dehydrogenation (PDH) reactions, with an emphasis on developments over the past ten years. A comprehensive summary is provided, encompassing the methodologies for preparing zeolite-supported metal catalysts, regulating the active site, modifying the pore structure and acid properties of zeolites, as well as their catalytic performances in PDH. The analyses emphasize the role and mechanism of metal-metal and/or metal-zeolite interactions in adjusting the structure of active sites, stabilizing metal species, enhancing catalytic performance and facilitating propylene production. Finally, the future directions of catalyst design for alkane dehydrogenation are envisioned.

Materials science has now progressed to the fine atomic scale, demonstrating a broad spectrum of applications in photocatalysis, electrocatalysis, and thermal catalysis. Triatomic catalysts (TACs) have attracted considerable attention, primarily because of their ultra-high atomic utilization efficiency, as well as their remarkable catalytic activity and selectivity. TACs currently face multiple challenges that affect their durability, efficiency, and stability. The high surface energy of atoms and limited loading capacity further restrict their practical applications. To address these issues and meet the strict requirements for catalyst applications, researchers have devoted themselves to developing novel metal TACs with features of cost-effectiveness, high stability, excellent activity, high loading capacity, and maintained selectivity. This review systematically summarizes the recent progress in TACs, covering preparation methods, support material selection, and application fields, with an emphasis on the role of carriers in influencing TAC performance. Furthermore, the potential of TACs in energy conversion reactions, such as oxygen reduction reaction, CO₂ reduction reaction, and N₂ reduction reaction, is discussed. The existing challenges of TACs and key directions for future research in this field are also elaborated in a systematic manner.