Professor Kazunari Domen at the Shinshu University and the University of Tokyo has pioneered materials and techniques for solar-driven water splitting using photocatalysts, a promising technology for contributing to the construction of a sustainable and carbon-neutral society. In this paper, we summarize his groundbreaking contributions to photocatalytic water splitting and, more broadly, photocatalytic research. We highlight various novel functional photocatalytic materials, including oxides, (oxy)nitrides, and oxysulfides, along with innovative techniques such as cocatalyst engineering and Z-scheme system construction developed by the Domen Group. His team has also pioneered readily accessible and cost-effective photo(electro)chemical device fabrication methods, such as the particle-transfer method and thin-film-transfer method. Furthermore, their research has made significant contributions to understanding the (photo)catalytic mechanisms using advanced characterization techniques. Together with his research team, Professor Domen has set many milestones in the field of photocatalytic overall water splitting, notably demonstrating the first scalable and stable 100 m² solar H₂ production system using only water and sunlight. His work has revealed the potential for practical solar H₂ production from water and sunlight, and highlighted the application of fundamental principles, combined with chemical and materials science tools, to design effective photocatalytic systems. Through this review, we focus on his research and the foundational design principles that can inspire the development of efficient photocatalytic systems for water splitting and solar fuel production. By building on his contributions, we anticipate a significant impact on addressing major global energy challenges.

Harnessing solar energy for renewable fuel production through artificial photosynthesis offers an ideal solution to the current energy and environmental crises. Among various methods, photoelectrochemical (PEC) water splitting stands out as a promising approach for direct solar-driven hydrogen production. Enhancing the efficiency and stability of photoelectrodes is a key focus in PEC water-splitting research. Tantalum nitride (Ta₃N₅), with its suitable band gap and band-edge positions for PEC water splitting, has emerged as a highly promising photoanode material. This review begins by introducing the history and fundamental characteristics of Ta₃N₅, emphasizing both its advantages and challenges. It then explores methods to improve light absorption efficiency, charge separation and transfer efficiency, surface reaction rate, and the stability of Ta₃N₅ photoanodes. Additionally, the review discusses the progress of research on tandem PEC cells incorporating Ta₃N₅ photoanodes. Finally, it looks ahead to future research directions for Ta₃N₅ photoanodes. The strategic approach outlined in this review can also be applied to other photoelectrode materials, providing guidance for their development.

Electrochemical reduction of CO₂ (CO₂RR) to form high-energy-density and high-value-added multicarbon products has attracted much attention. Selective reduction of CO₂ to C₂₊ products face the problems of low reaction rate, complex mechanism and low selectivity. Currently, except for a few examples, copper-based catalysts are the only option capable of achieving efficient generation of C₂₊ products. However, the continuous dynamic reconstruction of the catalyst causes great difficulty in understanding the structure-performance relationship of CO₂RR. In this review, we first discuss the mechanism of C₂₊ product generation. The structural factors promoting C₂₊ product generation are outlined, and the dynamic evolution of these structural factors is discussed. Furthermore, the effects of electrolyte and electrolysis conditions are reviewed in a vision of dynamic surface. Finally, further exploration of the reconstruction mechanism of Cu-based catalysts and the application of emerging robotic AI chemists are discussed.

Green hydrogen is the most promising option and a two in one remedy that resolve the problem of both energy crisis and environmental pollution. Wide band gap semiconductors (WBG) (E_g >2 eV) are the most prominent and leading catalytic materials in both electro and photocatalytic water splitting (WSR); two sustainable methods of green hydrogen production. WBGs guarantee long life time of photo charge carriers and thereby surface availability of electrons and holes. Therefore, WBG (with appropriate VB-CB potential) along with small band gap materials or sensitizers can yield extraordinary photocatalytic system for hydrogen production under solar light. The factors such as, free energy of hydrogen adsorption (∆G_H^*) close to zero, high electron mobility, great thermal as well as electro chemical stability and high tunability make WBG an interesting and excellent catalyst in electrolysis too. Taking into account the current relevance and future scope, the present review article comprehends different dimensions of WBG materials as an electro/photo catalyst for hydrogen evolution reaction. Herein WBG semiconductors are presented under various classes; viz. II-VI, III-V, III-VI, lanthanide oxides, transition metal based systems, carbonaceous materials and other systems such as SiC and MXenes. Catalytic properties of WBGs favorable for hydrogen production are then reviewed. A detailed analysis on relationship between band structure and activity (electro, photo and photo-electrochemical WSR) is performed. The challenges involved in these reactions as well as the direction of advancement in WBG based catalysis are also debated. By virtue of this article authors aims to guideline and promote the development of new WBG based electro/photocatalyst for HER and other applications.

Investigating highly effective electrocatalysts for high-temperature proton exchange membrane fuel cells (HT-PEMFC) requires the resistance to phosphate acid (PA) poisoning at cathodic oxygen reduction reaction (ORR). Recent advancements in catalysts have focused on alleviating phosphoric anion adsorption on Pt-based catalysts with modified electronic structure or catalytic interface and developing Fe-N-C based catalysts with immunity of PA poisoning. Fe-N-C-based catalysts have emerged as promising alternatives to Pt-based catalysts, offering significant potential to overcome the characteristic adsorption of phosphate anion on Pt. An overview of these developments provides insights into catalytic mechanisms and facilitates the design of more efficient catalysts. This review begins with an exploration of basic poisoning principles, followed by a critical summary of characterization techniques employed to identified the underlying mechanism of poisoning effect. Attention is then directed to endeavors aimed at enhancing the HT-PEMFC performance by well-designed catalysts. Finally, the opportunities and challenges in developing the anti-PA poisoning strategy and practical HT-PEMFC is discussed. Through these discussions, a comprehensive understanding of PA-poisoning bottlenecks and inspire future research directions is aim to provided.

Metal-organic frameworks (MOFs) serve as highly effective hosts for ultrasmall metal species, creating advanced nanocatalysts with superior catalytic performance, stability, and selective activity. The synergistic interplay between metal species confined within MOF nanopores and their active sites enhances catalytic efficiency in CO₂ hydrogenation reactions. Herein, recent advancements in synthesizing metal-confined MOFs are discussed, along with their applications in catalyzing CO₂ conversion through various methods such as photocatalysis, thermal catalysis, and photothermal catalysis. Additionally, we further emphasize the fundamental principles and factors that influence various types of catalytic CO₂ hydrogenation reactions, while offering insights into future research directions in this dynamic field.

Methane (CH₄) has a higher heat capacity (104.9 kcal/mol) than carbon dioxide (CO₂), and this has inspired research aimed at reducing methane levels to retard global warming. Hydroxylation under ambient conditions through methanotrophs can provide crucial information for understanding the harsh C-H activation of methane. Soluble methane monooxygenase (sMMO) belongs to the bacterial multi-component monooxygenase superfamily and requires hydroxylase (MMOH), regulatory (MMOB), and reductase (MMOR) components. Recent structural and biophysical studies have demonstrated that these components accelerate and retard methane hydroxylation in MMOH through protein-protein interactions. Complex structures of sMMO, including MMOH-MMOB and MMOH-MMOD, illustrate how these regulatory and inhibitory components orchestrate the di-iron active sites located within the four-helix bundles of MMOH, specifically at the docking surface known as the canyon region. In addition, recent biophysical studies have demonstrated the role of MmoR, a σ⁵⁴-dependent transcriptional regulator, in regulating sMMO expression. This perspective article introduces remarkable discoveries in recent reports on sMMO components that are crucial for understanding sMMO expression and activities. Our findings provide insight into how sMMO components interact with MMOH to control methane hydroxylation, shedding light on the mechanisms governing sMMO expression and the interactions between activating enzymes and promoters.

Semiconductor-cocatalyst interfacial electron transfer has widely been considered as a fast step occurring on picosecond-microsecond timescale in photocatalytic reaction. However, the formed potential barriers severely slow this interfacial electronic process by thermionic emission. Although trap-assisted charge recombination can transfer electrons from semiconductor to cocatalyst and can even be evident under weak illumination, the parallel connection with thermionic emission makes the photocatalytic photon utilization encounter a minimum along the variation of light intensity. By this cognition, the light-intensity-dependent photocatalytic behaviors can be predicted by simulating the photoinduced semiconductor-cocatalyst interfacial electron transfer that mainly determines the reaction rate. We then propose a (photo)electrochemical method to evaluate the time constants for occurring this interfacial electronic process in actual photocatalytic reaction without relying on extremely high photon flux that is required to generate discernible optical signal in common instrumental methods based on ultrafast pulse laser. The evaluated decisecond-second timescale can accurately guide us to develop certain strategies to facilitate this rate-determining step to improve photon utilization.

Vicinal diamines are key motifs widely-found in many pharmaceuticals and biologically active molecules. An appealing approach for synthesizing these molecules is the amination of enamines, but few examples have been explored. With the utilization of nitrogen-centered radicals (NCRs), here we present the development of a dual bio-/photo-catalytic system for achieving enantioselective hydroamination of enamides, which can give easy access to diverse enantioenriched vicinal diamines. These reactions progress efficiently under green light excitation and exhibit excellent enantioselectivities (up to >99% enantiomeric excess). Mechanistic studies uncovered the synergistic effect of the enzyme and the externally added organophotoredox catalyst Rhodamine B (RhB). This work demonstrates the effectiveness of photobiocatalysis to generate and control high-energy radical intermediates, addressing a long-standing challenge in chemical synthesis.

Methyl methoxyacetate (MMAc) and methyl formate (MF) can be produced directly by heterogeneous zeolite-catalyzed carbonylation and disproportionation of dimethoxymethane (DMM), with near 100% selectivity for each process. Despite continuous research efforts, the insight into the reaction mechanism and kinetics theory are still in their nascent stage. In this study, ZEO-1 material, a zeolite with up to now the largest cages comprising 16×16-MRs, 16×12-MRs, and 12×12-MRs, was explored for DMM carbonylation and disproportionation reactions. The rate of MMAc formation based on accessible Brönsted acid sites is 2.5 times higher for ZEO-1 (Si/Al = 21) relative to the previously investigated FAU (Si/Al = 15), indicating the positive effect of spatial separation of active sites in ZEO-1 on catalytic activity. A higher MF formation rate is also observed over ZEO-1 with lower activation energy (79.94 vs. 95.19 kJ/mol) compared with FAU (Si/Al = 30). Two types of active sites are proposed within ZEO-1 zeolite: Site 1 located in large cages formed by 16×16-MRs and 16×12-MRs, which is active predominantly for MMAc formation, and Site 2 located in smaller cages for methyl formate/dimethyl ether formation. Kinetics investigation of DMM carbonylation over ZEO-1 exhibit a first-order dependence on CO partial pressure and a slightly inverse-order dependence on DMM partial pressure. The DMM disproportionation is nearly first-order dependence on DMM partial pressure, while it reveals a strongly inverse dependence with increasing CO partial pressure. Furthermore, ZEO-1 exhibits good catalytic stability, and almost no deactivation is observed during the more than 70 h test with high carbonylation selectivity of above 89%, due to the well-enhanced diffusion property demonstrated by intelligent-gravimetric analysis.

Designing Fischer-Tropsch synthesis (FTS) catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge. Herein, we selectively introduced Co nanoparticles (NPs) into the micropores and mesopores of an ordered mesoporous MFI zeolite (OMMZ) through impregnation, which controlled the carbon number distribution in the FTS products by tuning the position of catalytic active sites in differently sized pores. The Co precursors coordinated by acetate with a size of 9.4 × 4.2 × 2.5 Å and by 2,2'-bipyridine with a size of 9.5 × 8.7 × 7.9 Å, smaller and larger than the micropores (ca. 5.5 Å) of MFI, made the Co species incorporated in OMMZ's micropores and mesopores, respectively. The carbon number products synthesized with the Co NPs confined in mesopores were larger than that in micropores. The high jet and diesel selectivities of 66.5% and 65.3% were achieved with Co NPs confined in micropores and mesopores of less acidic Na-type OMMZ, respectively. Gasoline and jet selectivities of 76.7% and 70.8% were achieved with Co NPs confined in micropores and mesopores of H-type OMMZ with Brönsted acid sites, respectively. A series of characterizations revealed that the selective production of diesel and jet fuels was due to the C-C cleavage suppressing of heavier hydrocarbons by the Co NPs located in mesopores.

Inefficient photo-carrier separation and sluggish photoreaction dynamics appreciably undermine the photocatalytic decontamination efficacy of photocatalysts. Herein, an S-scheme Mn_0.5Cd_0.5S/Bi₂MoO₆ heterojunction with interfacial Mo-S chemical bond is designed as an efficient photocatalyst. In this integrated photosystem, Bi₂MoO₆ and Mn_0.5Cd_0.5S function as oxidation and reduction centers of Mn_0.5Cd_0.5S/Bi₂MoO₆ microspheres, respectively. Importantly, the unique charge transfer mechanism in the chemically bonded S-scheme heterojunction with Mo-S bond as atom-scale charge transport highway effectively inhibits the photocorrosion of Mn_0.5Cd_0.5S and the recombination of photo-generated electron-hole pairs, endowing Mn_0.5Cd_0.5S/Bi₂MoO₆ photocatalyst with excellent photocatalytic decontamination performance and stability. Besides, integration of Mn_0.5Cd_0.5S nanocrystals into Bi₂MoO₆ improves hydrophilicity, conducive to the photoreactions. Strikingly, compared with Mn_0.5Cd_0.5S and Bi₂MoO₆, the Mn_0.5Cd_0.5S/Bi₂MoO₆ unveils much augmented photoactivity in tetracycline eradication, among which Mn_0.5Cd_0.5S/Bi₂MoO₆-2 possesses the highest activity with the rate constant up to 0.0323 min^‒1, prominently outperforming other counterparts. This research offers a chemical bonding engineering combining with S-scheme heterojunction strategy for constructing extraordinary photocatalysts for environmental purification.

Recent studies have revealed the extraordinary performance of zirconium oxide in propane dehydrogenation, which is attributed to the excellent reactivity of the coordinatively unsaturated zirconium sites (Zr_cus) around the oxygen vacancies. The origin of the enhanced catalytic activity of ZrO₂ with defective tetrahedral Zr sites was examined by direct comparison with its pristine counterpart in the current study. Electronic-structure analysis revealed that electrons from oxygen removal were localized within vacancies on the defective surface, which directly attacked the C-H bond in propane. The involvement of localized electrons activates the C-H bond via back-donation to the antibonding orbital on the defective surface; conversely, charge is transferred from propane to the pristine surfaces. The barrier for the first C-H bond activation is clearly significantly reduced on the defective surfaces compared to that on the pristine surfaces, which verifies the superior activity of Zr_cus. Notably, however, the desorption of both propene and hydrogen molecules from Zr_cus is more difficult due to strong binding. The calculated turnover frequency (TOF) for propene formation demonstrates that the pristine surfaces exhibit better catalytic performance at lower temperatures, whereas the defective surfaces have a larger TOF at high temperatures. However, the rate-determining step and reaction order on the defective surface differ from those on the pristine surface, which corroborates that the catalysts follow different mechanisms. A further optimization strategy was proposed to address the remaining bottlenecks in propane dehydrogenation on zirconium oxide.

It is a challenging task to efficiently convert deleterious hydrogen sulfide (H₂S) into less harmful products such as SO₄^2- species. In an effort to address such issue, a step-scheme (S-scheme) heterojunction photocatalyst has been built by concatenating TiO₂ (P25) and ultrathin Bi₄O₅Br₂ into TiO₂/Bi₄O₅Br₂ (namely, x-TB-y: x and y denote the molar ratio of TiO₂:Bi₄O₅Br₂ and pH value for solution-based synthesis, respectively) via in-situ hydrothermal method. The S-scheme charge transfer pathway in TB is confirmed by electron spin resonance and band structure analysis while experimental data and density functional theory calculations suggest the formation of an internal electric field to facilitate the separation and transfer of photoinduced charge carriers. Accordingly, the optimized heterojunction photocatalyst, i.e., 5-TB-9, showcases significantly high (> 99%) removal efficiency against 10 ppm H₂S in a 17 L chamber within 12 minutes (removal kinetic rate r: 0.7 mmol·h^-1·g^-1, specific clean air delivery rate SCADR: 5554 L·h^-1·g^-1, quantum yield QY: 3.24 E-3 molecules·photon^-1, and space-time yield STY: 3.24 E-3 molecules·photon^-1·mg^-1). Combined analysis of in-situ diffuse reflectance infrared Fourier transform adsorption spectra and gas chromatography-mass spectrometry allows to evaluate the mechanisms leading to the complete degradation of H₂S (i.e., into SO₄^2- without forming any intermediate species). This work demonstrates the promising remediation potential of an S-scheme TiO₂/Bi₄O₅Br₂ photocatalyst against hazardous H₂S gas for sustainable environmental remediation.

Storing solar energy in battery systems is crucial to achieving a green and sustainable society. However, the efficient development of photo-enhanced zinc-air batteries (ZABs) is limited by the rapid recombination of photogenerated carriers on the photocathode. In this work, the visible-light-driven CoS₂/CuS@CNT-C₃N₄ photocatalyst with unique petal-like layer structure was designed and developed, which can be used as air electrode for visible-light-driven ZABs. The superior performance of ZABs assembled by CoS₂/CuS@CNT-C₃N₄ was mainly attributed to the successful construction of Schottky heterojunction between g-C₃N₄ and carbon nanotubes (CNTs), which accelerates the transfer of electrons from g-C₃N₄ to CoS₂/CuS cocatalysts, improves the carrier separation ability, and extends the carrier lifetime. Thereinto, the visible-driven ZABs assembled by CoS₂/CuS@CNT-C₃N₄ photocatalyst has a power density of 588.90 mW cm^-2 and a charge-discharge cycle of 643 h under visible light irradiation, which is the highest performance ever reported for photo-enhanced ZABs. More importantly, the charge-discharge voltage drop of ZABs was only 0.54 V under visible light irradiation, which is significantly lower than the voltage drop (0.94 V) in the dark. This study provides a new idea for designing efficient and stable visible-light-driven ZABs cathode catalysts.

Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO₂ reduction and H₂O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts, while concurrently preventing side reactions and photocorrosion on the semiconductor surface. Herein, Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios (Ni_xCo_1-x(OH)₂, x = 1, 0.75, 0.5, 0.25, and 0) were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu₂O nanosheets and Fe₂O₃ nanoplates to form a series of Cu₂O/Fe₂O₃@Ni_xCo_1-x(OH)₂ (CF@NiCo) photocatalysts. The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)₂ not only modulates the energy band structure of Ni_xCo_1-x(OH)₂, balances the electron- and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction, but also regulates the d-band center of Ni_xCo_1-x(OH)₂, reinforcing the adsorption and activation of CO₂ and H₂O on the cocatalyst surface and lowering the rate-limiting barriers in the CO₂-to-CO and H₂O-to-O₂ conversion. Benefiting from the Ni-Co synergy, the redox reactions proceed stoichiometrically. The optimized CF@Ni_0.75Co_0.25 achieves CO and O₂ yields of 552.7 and 313.0 μmol g_cat^-1 h^-1, respectively, 11.3/9.9, 1.6/1.7, and 4.5/5.9-fold higher than those of CF, CF@Ni, and CF@Co. This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.

Photocatalysis provides a promising solution to the worldwide shortages of energy and industrially important raw materials by utilizing sunlight for coupled hydrogen (H₂) production with controllable organic transformation. Herein, we demonstrate that PtFeNiCoCu high-entropy alloy (HEA) nanocrystals can act as efficient cocatalysts for H₂ evolution coupled with selective oxidation of cinnamyl alcohol to cinnamaldehyde by cubic cadmium sulfide (CdS) quantum dots (QDs) with uniform sizes of 4.0 ± 0.5 nm. HEA nanocrystals were prepared via a simple solvothermal approach, and were successfully integrated with CdS QDs by an electrostatic self-assembly method to construct HEA/CdS composites. The optimized HEA/CdS sample presented an enhanced photocatalytic H₂ production rate of 7.15 mmol g^-1 h^-1, which was 13 times that of pure CdS QDs. Moreover, a cinnamyl alcohol conversion of 96.2% with cinnamaldehyde selectivity of 99.5% was achieved after photoreaction for 3 h. The integration of HEA with CdS QDs extended the optical absorption edge from 475 to 484 nm. From d-band center analysis, Pt atoms in the HEA are the active sites for H₂ evolution, exhibiting higher catalytic activity than pure Pt. Meanwhile, the band structure of the CdS QDs enables the oxidative transformation of cinnamyl alcohol to cinnamaldehyde with high selectivity. Moreover, femtosecond transient absorption spectroscopy shows that HEA can significantly promote the separation of photogenerated carriers in CdS, which is vital for achieving enhanced photocatalytic activity. This work inspires atomic-level design of photocatalytic materials for coordinated production of green energy carriers and value-added products.

Polyhydroxyalkanoate (PHA), a well-known biodegradable polymer, features β-lactones as its monomers, which can be selectively synthesized through ring-expansion carbonylation of epoxides using well-defined [Lewis acid]⁺[Co(CO)₄]^- catalysts. However, the decomposition of [Co(CO)₄]^- species at temperatures exceeding 80 °C presents a hurdle for the development of commercially viable processes under high-temperature reaction conditions to reduce reaction time. Drawing insights from stable {(acyl)Co(CO)_n} intermediates involved in historical HCo(CO)₄-catalyzed hydroformylation processes, we sought to the high-temperature catalytic activity of epoxide ring-expansion carbonylation. The developed catalyst system, [(acetyl)Co(CO)₂dppp] and [(TPP)CrCl], exhibited exceptional catalytic performance with an unprecedented initial turnover frequency of 4700 h^-1 at 100 °C and a turnover numbers of 93000. Notably, the catalyst displayed outstanding stability, operating at 80 °C for 168 h while selectively generating β-lactones.

Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals. Artificial cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available materials. Here we reported an artificial cascade biocatalysis comprising an epoxide hydrolase, an alcohol dehydrogenase, and a reductive aminase or an amine dehydrogenase. It can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields (up to 95%) and excellent stereoselectivity (up to 98% de) starting from readily available cyclohexene oxide without isolation of the intermediates. Additionally, the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.

Many strategies have been proposed to produce arenes from lignin as liquid fuel additives. However, the development of these methods is limited by the low yield of products, low atom utilization, and inefficient lignin depolymerization. Herein, we develop an energy-efficient synthetic method for the production of high-carbon-number arenes from sustainable lignin with a total yield of 23.1 wt%. Particularly, high carbon number arenes are obtained by fully utilizing the formaldehyde stabilizing additive and the methoxy group in lignin. The process begins with the reductive depolymerization of formaldehyde-stabilized lignin, followed by transmethylation between lignin monomers over Au/Nb₂O₅ catalyst, and the Ru/Nb₂O₅-catalyzed hydrodeoxygenation. This work demonstrates the potential of value-added arenes production directly from lignin.

CO₂ hydrogenation to value-added light olefins (C_2-4⁼) is crucial for the utilization and cycling of global carbon resource. Moderate CO₂ activation and carbon chain growth ability are key factors for iron-based catalysts for efficient CO₂ conversion to target C_2-4⁼ products. The electronic interaction and confinement effect of electron-deficient graphene inner surface on the active phase are effective to improve surface chemical properties and enhance the catalytic performance. Here, we report a core-shell FeCo alloy catalyst with graphene layers confinement prepared by a simple sol-gel method. The electron transfer from Fe species to curved graphene inner surface modifies the surface electronic structure of the active phase χ-(Fe_xCo_1-x)₅C₂ and improves CO₂ adsorption capacity, enhancing the efficient conversion of CO₂ and moderate C-C coupling. Therefore, the catalyst FeCoK@C exhibits C_2-4⁼ selectivity of 33.0% while maintaining high CO₂ conversion of 52.0%. The high stability without obvious deactivation for over 100 h and unprecedented C_2-4⁼ space time yield (STY) up to 52.9 mmol_CO2·g^-1·h^-1 demonstrate its potential for practical application. This work provides an efficient strategy for the development of high-performance CO₂ hydrogenation catalysts.

Understanding the influence of HCl on the NH₃-selective catalytic reduction reaction mechanism is crucial for designing highly efficient denitrification catalysts. The formation of chlorate species on the surface of the synthesized SbCeO_x catalyst, induced by HCl, significantly enhances low-temperature activity, as evidenced by a 30% increase in NO conversion at 155 °C. Furthermore, it improves N₂ selectivity at high temperatures, with a notable 17% increase observed at 405 °C. Both experimental results and density functional theory calculations confirm that chlorate species form at Ce sites. This formation facilitates the creation of oxygen vacancies, boosting the oxygen exchange capacity. It also increases NH₃ adsorption at the Ce sites, promotes the formation of Sb-OH, and reduces competitive OH adsorption on these sites. Notably, compared with the reaction mechanism without HCl, the presence of chlorate species enhances NH₃ adsorption and activation, which is vital for subsequent catalytic reactions.

The triple bond in N₂ has an extremely high bond energy and is thus difficult to break. N₂ is commonly converted into NH₃ artificially via the Haber-Bosch process, and NH₃ can be utilized to produce other nitrogen-containing chemicals. Here, we developed an electron catalyzed method to directly fix N₂ into azos, by pushing and pulling the electron into and from the aromatic halide with the cyclic voltammetry method. The round-trip journey of electron can successfully weaken the triple bond in N₂ through the electron pushing-induced aryl radical via a “brick trowel” transition state, and then produce the diazonium ions by pulling the electron out from the diazo radical intermediate. Different azos can be synthesized with this developed electron catalyzed approach. This approach provides a novel concept and practical route for the fixation of N₂ at atmospheric pressure into chemical products valuable for industrial and commercial applications.

Revealing the structure evolution of interfacial active species during a dynamic catalytic process is a challenging but pivotal issue for the rational design of high-performance catalysts. Here, we successfully prepare sub-nanometric Pt clusters (~0.8 nm) encapsulated within the defects of CeO₂ nanorods via an in-situ defect engineering methodology. The as-prepared Pt@d-CeO₂ catalyst significantly boosts the activity and stability in the water-gas shift (WGS) reaction compared to other analogs. Based on controlled experiments and complementary (in-situ) spectroscopic studies, a reversible encapsulation induced by active site transformation between the Pt²⁺-terminal hydroxyl and Pt^δ+-O vacancy species at the interface is revealed, which enables to evoke the enhanced performance. Our findings not only offer practical guidance for the design of high-efficiency catalysts but also bring a new understanding of the exceptional performance of WGS in a holistic view, which shows a great application potential in materials and catalysis.

Electrochemical nitrate (NO₃⁻) reduction offers a promising route for ammonia (NH₃) synthesis from industrial wastewater using renewable energy. However, achieving selective and active NO₃⁻ to NH₃ conversion at low potentials remains challenging due to complex multi-electron transfer processes and competing reactions. Herein, we tackle this challenge by developing a cascade catalysis approach using synergistic active sites at Cu-Fe₂O₃ interfaces, significantly reducing the NO₃⁻ to NH₃ at a low onset potential to about +0.4 V_RHE. Specifically, Cu optimizes *NO₃ adsorption, facilitating NO₃⁻ to nitrite (NO₂⁻) conversion, while adjacent Fe species in Fe₂O₃ promote the subsequent NO₂⁻ reduction to NH₃ with favorable *NO₂ adsorption. Electrochemical operating experiments, in situ Raman spectroscopy, and in situ infrared spectroscopy consolidate this improved onset potential and reduction kinetics via cascade catalysis. An NH₃ partial current density of ~423 mA cm⁻² and an NH₃ Faradaic efficiency (FE_NH3) of 99.4% were achieved at −0.6 V_RHE, with a maximum NH₃ production rate of 2.71 mmol h⁻¹ cm⁻² at −0.8 V_RHE. Remarkably, the half-cell energy efficiency exceeded 35% at −0.27 V_RHE (80% iR corrected), maintaining an FE_NH3 above 90% across a wide range of NO₃⁻ concentrations (0.05−1 mol L⁻¹). Using ¹⁵N isotopic tracing, we confirmed NO₃⁻ as the sole nitrogen source and attained a 98% NO₃⁻ removal efficiency. The catalyst exhibit stability over 106-h of continuous operation without noticeable degradation. This work highlights distinctive active sites in Cu-Fe₂O₃ for promoting the cascade NO₃⁻ to NO₂⁻ and NO₂⁻ to NH₃ electrolysis at industrial relevant current densities.