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Nitrate (NO 3 ‒ ) pollution poses significant threats to water quality and global nitrogen cycles. Alkaline electrocatalytic NO 3 ‒ reduction reaction (NO 3 RR) emerges as an attractive route for enabling NO 3 ‒ removal and sustainable ammonia (NH 3 ) synthesis. However, it suffers from insufficient proton (H + ) supply in high pH conditions, restricting NO 3 ‒ -to-NH 3 activity. Herein, we propose a halogen-mediated H + feeding strategy to enhance the alkaline NO 3 RR performance. Our platform achieves near-100% NH 3 Faradaic efficiency (pH = 14) with a current density of 2 A cm –2 and enables an over 99% NO 3 – -to-NH 3 conversion efficiency. We also convert NO 3 ‒ to high-purity NH 4 Cl with near-unity efficiency, suggesting a practical approach to valorizing pollutants into valuable ammonia products. Theoretical simulations and in situ experiments reveal that Cl-coordination endows a shifted d -band center of Pd atoms to construct local H + -abundant environments, through arousing dangling O-H water dissociation and fast *H desorption, for *NO intermediate hydrogenation and finally effective NO 3 ‒ -to-NH 3 conversion. Alkaline nitrate electroreduction to ammonia is restricted by insufficient H + supply. Here, the authors propose a halogen-mediated H + feeding strategy, by triggering dangling O-H water dissociation and fast *H desorption for *NO intermediate hydrogenation, to enhance the formation of ammonia.

Electrochemical CO 2 reduction to multicarbon products faces challenges of unsatisfactory selectivity, productivity, and long-term stability. Herein, we demonstrate CO 2 electroreduction in strongly acidic electrolyte (pH ≤ 1) on electrochemically reduced porous Cu nanosheets by combining the confinement effect and cation effect to synergistically modulate the local microenvironment. A Faradaic efficiency of 83.7 ± 1.4% and partial current density of 0.56 ± 0.02 A cm −2 , single-pass carbon efficiency of 54.4%, and stable electrolysis of 30 h in a flow cell are demonstrated for multicarbon products in a strongly acidic aqueous electrolyte consisting of sulfuric acid and KCl with pH ≤ 1. Mechanistically, the accumulated species (e.g., K + and OH − ) on the Helmholtz plane account for the selectivity and activity toward multicarbon products by kinetically reducing the proton coverage and thermodynamically favoring the CO 2 conversion. We find that the K + cations facilitate C-C coupling through local interaction between K + and the key intermediate *OCCO. Attaining high selectivity for CO 2 electroreduction in acid is usually difficult due to competing hydrogen evolution. Here, the authors demonstrate efficient CO 2 reduction to multicarbon products in strongly acidic medium (pH ≤ 1) on a porous Cu catalyst by combining confinement and cation effects.

Atomically dispersed transition metals on carbon-based aromatic substrates are an emerging class of electrocatalysts for the electroreduction of CO 2 . However, electron delocalization of the metal site with the carbon support via d-π conjugation strongly hinders CO 2 activation at the active metal centers. Herein, we introduce a strategy to attenuate the d-π conjugation at single Ni atomic sites by functionalizing the support with cyano moieties. In situ attenuated total reflection infrared spectroscopy and theoretical calculations demonstrate that this strategy increases the electron density around the metal centers and facilitates CO 2 activation. As a result, for the electroreduction of CO 2 to CO in aqueous KHCO 3 electrolyte, the cyano-modified catalyst exhibits a turnover frequency of ~22,000 per hour at −1.178 V versus the reversible hydrogen electrode (RHE) and maintains a Faradaic efficiency (FE) above 90% even with a CO 2 concentration of only 30% in an H-type cell. In a flow cell under pure CO 2 at −0.93 V versus RHE the cyano-modified catalyst enables a current density of −300 mA/cm 2 with a FE above 90%. Electroreduction of CO 2 on single atom catalysts is often hindered by electron delocalization of the metal sites. To improve CO 2 activation, here the authors functionalize the carbon support with cyano moieties, thereby attenuating metal-substrate conjugation and improving CO 2 to CO conversion.

Acidic CO 2 electroreduction to multi-carbon (C 2+ ) products using Cu-based catalyst has attracted considerable attention for CO 2 recycling due to high single-pass CO 2 utilization. However, its development is drastically limited by the poor stability, especially at high current density, caused by Cu dissolution/reconstruction during the reaction. Herein, we find the trace dissolved oxygen in the electrolyte accounts for the Cu dissolution/reconstruction and report an in-situ passivation strategy to prevent oxygen adsorption for inhibiting Cu dissolution/reconstruction for high stability CO 2 -to-C 2+ conversion. Theoretical and in situ spectroscopy demonstrate that aluminum citrate (AC) passivation layer decreases the adsorption of oxygen on Cu surface to effectively prevent the Cu oxidation, which is beneficial for the formation and adsorption of linearly bonded *CO toward C-C coupling. As the result, the Cu catalysts with AC layer achieve over 60% Faradaic efficiency C 2 H 4 and 38.7% energy efficiency to C 2+ for over 150 h stability at 500 mA cm −2 in strong acidic electrolyte. The use of Cu catalysts for the CO 2 reduction reaction is hindered by their poor stability. The authors find that traces dissolved oxygen in the electrolyte results in Cu dissolution/reconstruction and report an in-situ passivation strategy to prevent oxygen adsorption in high stability.

Single-atom catalysts (SACs) have received increasing attention due to their 100% atomic utilization efficiency. The electrochemical CO 2 reduction reaction (CO 2 RR) to CO using SAC offers a promising approach for CO 2 utilization, but achieving facile CO 2 adsorption and CO desorption remains challenging for traditional SACs. Instead of singling out specific atoms, we propose a strategy utilizing atoms from the entire lanthanide (Ln) group to facilitate the CO 2 RR. Density functional theory calculations, operando spectroscopy, and X-ray absorption spectroscopy elucidate the bridging adsorption mechanism for a representative erbium (Er) single-atom catalyst. As a result, we realize a series of Ln SACs spanning 14 elements that exhibit CO Faradaic efficiencies exceeding 90%. The Er catalyst achieves a high turnover frequency of ~130,000 h − 1 at 500 mA cm − 2 . Moreover, 34.7% full-cell energy efficiency and 70.4% single-pass CO 2 conversion efficiency are obtained at 200 mA cm − 2 with acidic electrolyte. This catalytic platform leverages the collective potential of the lanthanide group, introducing new possibilities for efficient CO 2 -to-CO conversion and beyond through the exploration of unique bonding motifs in single-atom catalysts. Single atom catalysts offer a promising approach for CO 2 electroreduction to CO, but achieving high efficiency remains challenging. Here, the authors report lanthanide single atom catalysts with the transition ability from bridge to linear adsorption that exhibit efficient CO production.

Electroreduction of nitrate (NO 3 ‒ ) to ammonia (NH 3 ) is a promising approach for addressing energy challenges. However, the activity is limited by NO 3 ‒ mass transfer, particularly at reduction potential, where an abundance of electrons on the cathode surface repels NO 3 ‒ from the inner Helmholtz plane (IHP). This constraint becomes pronounced as NO 3 ‒ concentration decreases, impeding practical applications in the conversion of NO 3 ‒ -to-NH 3 . Herein, we propose a generic strategy of catalyst bandstructure engineering for the enrichment of negatively charged ions through solid-liquid (S-L) junction-mediated charge rearrangement within IHP. Specifically, during NO 3 ‒ reduction, the formation of S-L junction induces hole transfer from Ag-doped MoS 2 (Ag-MoS 2 ) to electrode/electrolyte interface, triggering abundant positive charges on the IHP to attract NO 3 ‒ . Thus, Ag-MoS 2 exhibits a ~ 28.6-fold NO 3 ‒ concentration in the IHP than the counterpart without junction, and achieves near-100% NH 3 Faradaic efficiency with an NH 3 yield rate of ~20 mg h ‒1 cm ‒2 under ultralow NO 3 ‒ concentrations. Electroreduction of low-concentration NO 3 − to NH 3 is limited by NO 3 − mass transfer. Here, the authors propose a strategy for NO 3 − enrichment through charge rearrangement within the inner Helmholtz plane, achieving near-unity conversion of NO 3 − to NH 3 .

GH4099 is a nickel-based, high-temperature, precipitation-strengthened alloy with excellent mechanical properties and corrosion resistance, widely used in aerospace components. The performance of parts produced by additive manufacturing depends significantly on alloy powder quality and heat treatment. In this study, GH4099 alloy powder was prepared using the EIGA method, and its morphology, particle size distribution, and flowability were analyzed. The mechanical properties and microstructure of parts before and after solution-aging treatment were compared. Results showed that the powder had good sphericity and flowability, with a median diameter D50 of 28.88 μm. The formed parts underwent solution treatment at 1140 °C for 2 h followed by aging at 850 °C for 8 h. After heat treatment, the transverse tensile strength increased to 1122.11 MPa (+15.1%) and the yield strength to 866.56 MPa (+22.3%), while the longitudinal tensile strength reached 1116.81 MPa (+29.4%) and the yield strength 831.61 MPa (+35.2%). This improvement is attributed to the precipitation of γ′ phase. Fractographic analysis revealed a mixed fracture mode characterized by ductile dimples and cleavage facets, indicating that the alloy exhibits favorable toughness-related features under mechanical loading. These findings demonstrate the excellent microstructure and mechanical performance of GH4099 alloy in AM applications, providing a basis for its further use in high-performance aerospace components.

Reactive capture integrates CO 2 capture and electrochemical conversion into CO — a key building block in the synthesis of industrial chemicals and fuels — avoiding costly regeneration steps and improving efficiency. Amino acid salt solutions, which offer rapid CO 2 capture, facile CO 2 release, O 2 tolerance, and low toxicity, are promising sorbents for reactive capture. However, we find that amino acids can adsorb to common CO-producing catalysts, covering the active sites and deactivating the catalyst, and that they bind less to nickel phthalocyanine (NiPc). Still, when tested for reactive capture systems — where CO 2 supply is inherently limited — NiPc’s performance is constrained by its weak CO 2 adsorption and activation. Here we develop a nickel molecular catalyst supported on carbon nanotubes with a conjugated NiPc framework that resists amino acid adsorption and a coordinatively unsaturated Ni-N 3 structure that promotes CO 2 adsorption and enhances CO selectivity. As a result, we achieve 94% CO Faradaic efficiency at 100 mA cm –2 with an energy efficiency of 42% and an energy cost of 25 GJ t CO –1 . Reactive capture bypasses CO 2 regeneration, enabling efficient CO production but with low Faradaic efficiency. The authors report a Ni–N 3 molecular catalyst that resists amino acid adsorption and promotes efficient CO production in amino-acid systems.

Excessive consumption of fossil fuels gives rise to the increasing emission of carbon dioxide (CO2) in the atmosphere and furthers the ecocrisis. Electrochemical CO2 reduction (ECR) has both functions of dwindling greenhouse gas concentration and converting it into valuable products. Due to the intrinsic chemical inertness of CO2 molecules, the study on efficient and low‐cost catalysts has attracted much attention. Recently isolated atoms, dispersed in stable support, play an important role in decreasing energy barriers of intermediate steps and obtaining target products with high activity and selectivity for ECR. The effective regulation of central atoms or coordination environment is significant to realize the desired performances of ECR with a high efficiency and selectivity. Hence, a comprehensive summary about strategies for improving the performance of ECR on single atom catalysts (SACs) is necessary. Herein, the SACs on various supports are introduced, the methods to design stable SACs are discussed, and the strategies for tuning the performance of ECR on SACs are summarized. The localized environment manipulation is widely used for high‐performance SACs design, including regulating central atoms and coordination environment. Finally, the perspectives are discussed to shed light on the rational design of intriguing SACs for ECR. The performance of single atom catalysts (SACs) in carbon dioxide (CO2) electroreduction is closely related to the central atoms and its coordination environment. Strategies which include regulating the central atoms, coordination atoms, coordination number, and diatomic strategies are successfully developed to enhance the performance of SACs in CO2 reduction reaction.

Background/Aims: Previous studies have shown that oxidative damage is a main contributor to disc nucleus pulposus (NP) cell apoptosis. Aquaporin-3 (AQP-3) facilitates reactive oxygen species (ROS) scavenging and thus alleviates oxidative injury in other cells. This study aims to investigate the role and mechanism of AQP-3 in regulating NP cell apoptosis under oxidative damage. Methods: Rat NP cells were treated with H 2 O 2 for 48 hours, while control NP cells were free of H 2 O 2 . Recombinant AQP-3 lentiviral vectors were used to investigate the effect of enhanced AQP-3 expression levels in NP cells. NP cell apoptosis was assessed by flow cytometry, caspase-3 activity, gene expression of apoptosis-related molecules (Bax, Bcl-2 and caspase-3), and protein expression of cellular apoptosis markers (cleaved PARP and cleaved caspase-3). Additionally, intracellular ROS content and activity of the p38 MAPK pathway were evaluated. Results: Compared with the control NP cells, oxidative damage in the treatment cells significantly increased cell apoptosis ratios and caspase-3 activity, upregulated gene expression of Bax and caspase-3, downregulated gene expression of Bcl-2, and increased protein expression of cleaved PARP and cleaved caspase-3, as well as increased intracellular ROS content and activity of the p38 MAPK pathway. However, AQP-3 overexpression partly alleviated cell apoptosis, decreased intracellular ROS content, and inhibited the p38 MAPK pathway in NP cells under oxidative damage. Conclusion: Oxidative damage can significantly downregulate AQP-3 expression. Enhancing AQP-3 expression in NP cells partly attenuates cellular apoptosis through regulating the p38 MAPK pathway under oxidative damage.