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The susceptibility of the immune system to immunotoxic chemicals is evident, particularly in the thymus, a vital primary immune organ prone to atrophy due to exposure to toxicants. Fipronil (FPN), a widely used insecticide, is of concern due to its potential neurotoxicity, hepatotoxicity, and immunotoxicity. Our previous study showed that FPN disturbed the antigen-specific T-cell functionality in vivo. As T-cell lineage commitment and thymopoiesis are closely interconnected with the normal function of the T-cell-mediated immune responses, this study aims to further examine the toxic effects of FPN on thymocyte development. In this study, 4-week-old BALB/c mice received seven doses of FPN (1, 5, 10 mg/kg) by gavage. Thymus size, medulla/cortex ratio, total thymocyte counts, double-positive thymocyte population, and IL-7-positive cells decreased dose-dependently. IL-7 aids the differentiation of early T-cell precursors into mature T cells, and several essential genes contribute to the maturation of T cells in the thymus. Foxn1 ensures that the thymic microenvironment is suitable for the maturation of T-cell precursors. Lyl1 is involved in specifying lymphoid cells and maintaining T-cell development in the thymus. The c-Kit/SCF collaboration fosters a supportive thymic milieu to promote the formation of functional T cells. The expression of IL-7, IL-7R, c-Kit, SCF, Foxn1, and Lyl1 genes in the thymus was significantly diminished in FPN-treated groups with the concordance with the reduction of IL-7 signaling proteins (IL-7, IL-7R, c-KIT, SCF, LYL1, FOXO3A, and GABPA), suggesting that the dysregulation of T-cell lineage-related genes may contribute to the thymic atrophy induced by FPN. In addition, FPN disturbed the functionality of thymocytes with an increase of IL-4 and IFN-γ production and a decrease of IL-2 secretion after T-cell mitogen stimulation ex vivo. Collectively, FPN significantly deregulated genes related to T-cell progenitor differentiation, survival, and expansion, potentially leading to impaired thymopoiesis.
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Challenges in direct catalytic oxidation of biomass-derived aldehyde and alcohol into acid with high activity and selectivity hinder the widespread biomass application. Herein, we demonstrate that a Pd/Ni(OH)2 catalyst with abundant Ni2+-O-Pd interfaces allows electrooxidation of 5-hydroxymethylfurfural to 2, 5-furandicarboxylic acid with a selectivity near 100 % and 2, 5-furandicarboxylic acid yield of 97.3% at 0.6 volts (versus a reversible hydrogen electrode) in 1 M KOH electrolyte under ambient conditions. The rate-determining step of the intermediate oxidation of 5-hydroxymethyl-2-furancarboxylic acid is promoted by the increased OH species and low C-H activation energy barrier at Ni2+-O-Pd interfaces. Further, the Ni2+-O-Pd interfaces prevent the agglomeration of Pd nanoparticles during the reaction, greatly improving the stability of the catalyst. In this work, Pd/Ni(OH)2 catalyst can achieve 100% 5-hydroxymethylfurfural conversion and >90% 2, 5-furandicarboxylic acid selectivity in a flow-cell and work stably over 200 h under a fixed cell voltage of 0.85 V.
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High-entropy perovskite oxides are promising materials in the field of electrocatalysis due to their advantages such as large spatial composition regulation, entropy effects, and tunable material properties. However, the preparation of high-entropy perovskite oxides with stable and controllable structures still remains challenging. Herein, we fabricated a series of high-entropy perovskite oxide porous nanotubes (PNTs) by electrospinning as efficient electrocatalysts for the nitrate reduction reaction (NO3RR). We further revealed that the different diffusion and decomposition behaviors of metal ions and polymers during the calcination process are the key to the formation of high-entropy perovskite oxide PNTs. Especially, LaSrNiCoMnFeCuO3 PNTs show excellent performance of the NO3RR, achieving the maximum NH3 Faradaic efficiency of almost 100%, yield rate of 1657.5 µg h-1 mgcat.-1, and durable stability after successive cycling, being one of the best electrocatalysts for the NO3RR. The mechanism studies show that the charge redistribution induced by the multisite synergistic effect and abundant unsaturated sites in the high-entropy perovskite oxide PNTs favors the adsorption of NO3- and key intermediates and reduces the catalytic energy barrier, thus further achieving high NO3- conversion efficiency.
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A strain engineering strategy is crucial for designing a high-performance catalyst. However, how to control the strain in metastable phase two-dimensional (2D) materials is technically challenging due to their nanoscale sizes. Here, we report that cerium dioxide (CeO2) is an ideal loading material for tuning the in-plane strain in 2D metastable 1T-phase IrO2 (1T-IrO2) via an in situ growth method. Surprisingly, 5% CeO2 loaded 1T-IrO2 with 8% compressive strain achieves an overpotential of 194 mV at 10 mA cm-2 in a three-electrode system. It also retained a high current density of 900 mA cm-2 at a cell voltage of 1.8 V for a 400 h stability test in the proton-exchange membrane device. More importantly, the Fourier transform infrared measurements and density functional theory calculation reveal that the CeO2 induced strained 1T-IrO2 directly undergo the *O-*O radical coupling mechanism for O2 generation, totally different from the traditional adsorbate evolution mechanism in pure 1T-IrO2. These findings illustrate the important role of strain engineering in paving up an optimal catalytic pathway in order to achieve robust electrochemical performance.
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While high-entropy alloys, high-entropy oxides, and high-entropy hydroxides, are advanced as a novel frontier in electrocatalytic oxygen evolution, their inherent activity deficiency poses a major challenge. To achieve the unlimited goal to tailor the structure-activity relationship in multicomponent systems, entropy-driven composition engineering presents substantial potential, by fabricating high-entropy anion-regulated transition metal compounds as sophisticated oxygen evolution reaction electrocatalysts. Herein, a versatile 2D high-entropy metal phosphorus trisulfide is developed as a promising and adjustable platform. Leveraging the multiple electron couplings and d-p orbital hybridizations induced by the cocktail effect, the exceptional oxygen evolution catalytic activity is disclosed upon van der Waals material (MnFeCoNiZn)PS3, exhibiting an impressively low overpotential of 240 mV at a current density of 10 mA cm-2, a minimal Tafel slope of 32 mV dec-1, and negligible degradation under varying current densities for over 96 h. Density functional theory calculations further offer insights into the correlation between orbital hybridization and catalytic performance within high-entropy systems, underscoring the contribution of active phosphorus centers on the substrate to performance enhancements. Moreover, by achieving electron redistribution to optimize the electron coordination environment, this work presents an effective strategy for advanced catalysts in energy-related applications.
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Reversible protonic ceramic electrochemical cells (R-PCECs) offer the potential for high-efficiency power generation and green hydrogen production at intermediate temperatures. However, the commercial viability of R-PCECs is hampered by the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) within conventional air electrodes operating at reduced temperatures. To address this challenge, this work introduces a novel approach based on the simultaneous optimization of bulk-phase metal-oxygen bonds and in-situ formation of a metal oxide nano-catalyst surface modification. This strategy is designed to expedite the ORR/OER electrocatalytic activity of air electrodes exhibiting triple (O2-, H+, e-) conductivity. Specifically, this engineered air electrode nanocomposite-Ba(Co0.4Fe0.4Zr0.1Y0.1)0.95Ni0.05F0.1O2.9-δ demonstrates remarkable ORR/OER catalytic activity and exceptional durability in R-PCECs. This is evidenced by significantly improved peak power density from 626 to 996 mW cm-2 and highly stable reversibility over a 100-h cycling period. This research offers a rational design strategy to achieve high-performance R-PCEC air electrodes with superior operational activity and stability for efficient and sustainable energy conversion and storage.
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Hydrogen obtained from electrochemical water splitting is the most promising clean energy carrier, which is hindered by the sluggish kinetics of the oxygen evolution reaction (OER). Thus, the development of an efficient OER electrocatalyst using nonprecious 3d transition elements is desirable. Multielement synergistic effect and lattice oxygen oxidation are two well-known mechanisms to enhance the OER activity of catalysts. The latter is generally related to the high valence state of 3d transition elements leading to structural destabilization under the OER condition. We have found that Al doping in nanosheet Ni-Fe hydroxide exhibits 2-fold advantage: (1) a strong enhanced OER activity from 277 mV to 238 mV at 10 mA cm-2 as the Ni valence state increases from Ni3.58+ to Ni3.79+ observed from in situ X-ray absorption spectra. (2) Operational stability is strengthened, while weakness is expected since the increased NiIV content with 3d8L2 (L denotes O 2p hole) would lead to structural instability. This contradiction is attributed to a reduced lattice oxygen contribution to the OER upon Al doping, as verified through in situ Raman spectroscopy, while the enhanced OER activity is interpreted as an enormous gain in exchange energy of FeIV-NiIV, facilitated by their intersite hopping. This study reveals a mechanism of Fe-Ni synergy effect to enhance OER activity and simultaneously to strengthen operational stability by suppressing the contribution of lattice oxygen.
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Crystal-phase engineering that promotes the rearrangement of active atoms to form new structural frameworks achieves excellent result in the field of electrocatalysis and optimizes the performance of various electrochemical reactions. Herein, for the first time, it is found that the different components in metallic aerogels will affect the crystal-phase transformation, especially in high-entropy alloy aerogels (HEAAs), whose crystal-phase transformation during annealing is more difficult than medium-entropy alloy aerogels (MEAAs), but they still show better electrochemical performance. Specifically, PdPtCuCoNi HEAAs with the parent phase of face-centered cubic (FCC) PdCu possess excellent 89.24% of selectivity, 746.82 mmol h-1 g-1 cat. of yield rate, and 90.75% of Faraday efficiency for ethylamine during acetonitrile reduction reaction (ARR); while, maintaining stability under 50 h of long-term testing and ten consecutive electrolysis cycles. The structure-activity relationship indicates that crystal-phase regulation from amorphous state to FCC phase promotes the atomic rearrangement in HEAAs, thereby optimizing the electronic structure and enhancing the adsorption strength of reaction intermediates, improving the catalytic performance. This study provides a new paradigm for developing novel ARR electrocatalysts and also expands the potential of crystal-phase engineering in other application areas.
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Tumors developed in immunocompromised hosts are more immunogenic. However, few studies have addressed the potential mechanisms underlying the high immunogenicity of tumors found in a suppressed immune system. Therefore, we aimed to elucidate the impacts of the immune system on tumor behaviors and immunogenicity sculpting. A murine colorectal adenocarcinoma cell line, CT26wt, was administrated into immunocompetent (BALB/c) and immunocompromised (NOD.SCID) mice, respectively. On day 11, the CT26 cells slowly progressed in the NOD.SCID mice compared to the BALB/c mice. We then performed liquid chromatography-tandem mass spectrometry (LC-MS/MS) and analyzed the differentially expressed proteins (DEPs). The DEPs participated in numerous oncogenic pathways, PI3K/AKT/mTOR cell signaling, and the silencing of several tumor suppressors, such as PTEN and RBL1, during tumorigenesis. On day 34, the CT26/SCID tumors inversely became malignant counterparts; then the CT26/SCID tumors were harvested and re-inoculated into immunocompetent mice (CT26/SCID-Re tumors) to determine the immunogenicity. The CT26/SCID-Re tumor growth rate significantly decreased. Furthermore, increased infiltrations of dendritic cells and tumor-infiltrating T lymphocytes were found in the CT26/SCID-Re tumors. These findings suggest that immunogenic tumors might express multiple tumor rejection antigens, unlike wild-type tumors, and attract more immune cells, therefore decreasing the growth rate. Collectively, our study first revealed that in immunodeficient hosts, tumor suppressors were silenced and oncogenic signaling pathways were changed during the initial phase of tumor development. With tumor progression, the tumor antigens were overexpressed, exhibiting elevated immunogenicity. This study offers a hint on the mechanisms of tumorigenesis and provides a niche for investigating the interaction between host immunity and cancer development.
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Innovative topical bioregenerative materials promoting corneal stromal healing provide valuable alternatives for treating patients with deep corneal ulcers, and particularly beneficial for those with a higher anaesthetic risk. This study aimed to investigate the effects of topical amniotic membrane suspension (AMS) and ReGeneraTing Agent (RGTA) on surgically induced deep stromal ulcers in rats. Eighteen Sprague-Dawley rats were divided into 3 treatment groups: control group (topical normal saline, TID); AMS group (topical AMS, TID); RGTA group (topical RGTA, Q2D). Corneal microsurgery was used to create deep stromal ulcer. Evaluations were performed by corneal opacity grading, spectral domain optical coherence tomography (SD-OCT), histopathology, and immunohistochemistry. One-way ANOVA and Dunnett's test were used for statistical analysis. By the seventh day of treatment, both the AMS and RGTA groups showed significantly greater thickness in corneal stroma (both p-value < 0.05) than the control group. Additionally, the RGTA group exhibited a significantly higher degree of myofibroblast infiltration in the stroma and a greater level of corneal opacity (p < 0.05). No significant differences in the count of inflammatory cells were noted. In conclusion, both AMS and RGTA have demonstrated effectiveness in promoting the early stages of stromal wound healing and wound defect recovery in our research. Both AMS and RGTA have good potential for treating deep corneal ulcers in small animals practice. Further research is necessary to investigate the long-term effects and mechanism of using topical AMS and RGTA on treating deep corneal ulcer in clinical practice.
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Anion exchange membrane fuel cells are a potentially cost-effective energy conversion technology, however, the electrocatalyst for the anodic hydrogen oxidation reaction (HOR) suffers from sluggish kinetics under alkaline conditions. Herein, we report that Ru-based nanosheets with amorphous-crystalline heterointerfaces of Ru and Ti-doped RuO2 (a/c-Ru/Ti-RuO2) can serve as a highly efficient HOR catalyst with a mass activity of 4.16 A mgRu-1, which is 19.8-fold higher than that of commercial Pt/C. Detailed characterization studies show that abundant amorphous-crystalline heterointerfaces of a/c-Ru/Ti-RuO2 nanosheets provide oxygen vacancies and unsaturated coordination bonds for balancing adsorption of hydrogen and hydroxyl species on Ru active sites to elevate HOR activity. Moreover, Ti doping can facilitate CO oxidation, leading to enhanced strength to CO poisoning. This work provides a strategy for enhancing alkaline HOR performance over Ru-based catalysts with heteroatom and heterointerface dual-engineering, which will attract immediate interest in chemistry, materials science and beyond.
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Photothermal catalysis exhibits promising prospects to overcome the shortcomings of high-energy consumption of traditional thermal catalysis and the low efficiency of photocatalysis. However, there is still a challenge to develop catalysts with outstanding light absorption capability and photothermal conversion efficiency for the degradation of atmospheric pollutants. Herein, we introduced the Co3O4 layer and Pt nanoclusters into the three-dimensional (3D) porous membrane through the atomic layer deposition (ALD) technique, leading to a Pt/Co3O4/AAO monolithic catalyst. The 3D ordered nanochannel structure can significantly enhance the solar absorption capacity through the light-trapping effect. Therefore, the embedded Pt/Co3O4 catalyst can be rapidly heated and the O2 adsorbed on the Pt clusters can be activated to generate sufficient O2- species, exhibiting outstanding activity for the diverse VOCs (toluene, acetone, and formaldehyde) degradation. Optical characterization and simulation calculation confirmed that Pt/Co3O4/AAO exhibited state-of-the-art light absorption and a notable localized surface plasmon resonance (LSPR) effect. In situ diffuse reflectance infrared Fourier transform spectrometry (in situ DRIFTS) studies demonstrated that light irradiation can accelerate the conversion of intermediates during toluene and acetone oxidation, thereby inhibiting byproduct accumulation. Our finding extends the application of AAO's optical properties in photothermal catalytic degradation of air pollutants.
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Acetona , Cobalto , Óxidos , Tolueno , Oxidación-Reducción , Catálisis , Tolueno/análisis , Tolueno/químicaRESUMEN
Exploring an active and cost-effective electrocatalyst alternative to carbon-supported platinum nanoparticles for alkaline hydrogen evolution reaction (HER) have remained elusive to date. Here, we report a catalyst based on platinum single atoms (SAs) doped into the hetero-interfaced Ru/RuO2 support (referred to as Pt-Ru/RuO2), which features a low HER overpotential, an excellent stability and a distinctly enhanced cost-based activity compared to commercial Pt/C and Ru/C in 1 M KOH. Advanced physico-chemical characterizations disclose that the sluggish water dissociation is accelerated by RuO2 while Pt SAs and the metallic Ru facilitate the subsequent H* combination. Theoretical calculations correlate with the experimental findings. Furthermore, Pt-Ru/RuO2 only requires 1.90 V to reach 1 A cm-2 and delivers a high price activity in the anion exchange membrane water electrolyzer, outperforming the benchmark Pt/C. This research offers a feasible guidance for developing the noble metal-based catalysts with high performance and low cost toward practical H2 production.
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Retinoic acid-induced 1 (RAI1) encodes a transcriptional regulator critical for brain development and function. RAI1 haploinsufficiency in humans causes a syndromic autism spectrum disorder known as Smith-Magenis syndrome (SMS). The neuroanatomical distribution of RAI1 has not been quantitatively analyzed during the development of the prefrontal cortex, a brain region critical for cognitive function and social behaviors and commonly implicated in autism spectrum disorders, including SMS. Here, we performed comparative analyses to uncover the evolutionarily convergent and divergent expression profiles of RAI1 in major cell types during prefrontal cortex maturation in common marmoset monkeys (Callithrix jacchus) and mice (Mus musculus). We found that while RAI1 in both species is enriched in neurons, the percentage of excitatory neurons that express RAI1 is higher in newborn mice than in newborn marmosets. By contrast, RAI1 shows similar neural distribution in adult marmosets and adult mice. In marmosets, RAI1 is expressed in several primate-specific cell types, including intralaminar astrocytes and MEIS2-expressing prefrontal GABAergic neurons. At the molecular level, we discovered that RAI1 forms a protein complex with transcription factor 20 (TCF20), PHD finger protein 14 (PHF14), and high mobility group 20A (HMG20A) in the marmoset brain. In vitro assays in human cells revealed that TCF20 regulates RAI1 protein abundance. This work demonstrates that RAI1 expression and protein interactions are largely conserved but with some unique expression in primate-specific cells. The results also suggest that altered RAI1 abundance could contribute to disease features in disorders caused by TCF20 dosage imbalance.
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Trastorno del Espectro Autista , Síndrome de Smith-Magenis , Transactivadores , Animales , Ratones , Trastorno del Espectro Autista/genética , Callithrix , Neuronas GABAérgicas , Proteínas del Grupo de Alta Movilidad , Factores de Transcripción/genética , Transactivadores/genéticaRESUMEN
Noble metals have been widely used in catalysis, however, the scarcity and high cost of noble metal motivate researchers to balance the atomic efficiency and atomic density, which is formidably challenging. This article proposes a robust strategy for fabricating 3D amorphous noble metal-based oxides with simultaneous enhancement on atomic efficiency and density with the assistance of atomic channels, where the atomic utilization increases from 18.2% to 59.4%. The unique properties of amorphous bimetallic oxides and formation of atomic channels have been evidenced by detailed experimental characterizations and theoretical simulations. Moreover, the universality of the current strategy is validated by other binary oxides. When Cu2IrOx with atomic channels (Cu2IrOx-AE) is used as catalyst for oxygen evolution reaction (OER), the mass activity and turnover frequency value of Cu2IrOx-AE are 1-2 orders of magnitude higher than CuO/IrO2 and Cu2IrOx without atomic channels, largely outperforming the reported OER catalysts. Theoretical calculations reveal that the formation of atomic channels leads to various Ir sites, on which the proton of adsorbed *OH can transfer to adjacent O atoms of [IrO6]. This work may attract immediate interest of researchers in material science, chemistry, catalysis, and beyond.
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Reversible proton ceramic electrochemical cells are promising solid-state ion devices for efficient power generation and energy storage, but necessitate effective air electrodes to accelerate the commercial application. Here, we construct a triple-conducting hybrid electrode through a stoichiometry tuning strategy, composed of a cubic phase Ba0.5Sr0.5Co0.8Fe0.2O3-δ and a hexagonal phase Ba4Sr4(Co0.8Fe0.2)4O16-δ. Unlike the common method of creating self-assembled hybrids by breaking through material tolerance limits, the strategy of adjusting the stoichiometric ratio of the A-site/B-site not only achieves strong interactions between hybrid phases, but also can efficiently modifies the phase contents. When operate as an air electrode for reversible proton ceramic electrochemical cell, the hybrid electrode with unique dual-phase synergy shows excellent electrochemical performance with a current density of 3.73 A cm-2 @ 1.3 V in electrolysis mode and a peak power density of 1.99 W cm-2 in fuel cell mode at 650 °C.
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Amorphous nanomaterials have drawn extensive attention owing to their unique features, while amorphization on noble metal nanomaterials still remains formidably challenging. Herein, we demonstrate a universal strategy to synthesize amorphous Pd-based nanomaterials from unary to quinary metals through the introduction of phosphorus (P). The amorphous Pd-based nanoparticles (NPs) exhibit generally promoted oxygen reduction reaction (ORR) activity and durability compared with their crystalline counterparts. Significantly, the quinary P-PdCuNiInSn NPs, benefiting from the amorphous structure and multimetallic component effect, exhibit mass activities as high as 1.04 A mgPd-1 and negligible activity decays of 1.8% among the stability tests, which are much better than values for original Pd NPs (0.134 A mgPd-1 and 28.4%). Experimental and theoretical analyses collectively reveal that the synergy of P-induced amorphization and the expansion of metallic components can considerably lower the free energy changes in the rate-determined step, thereby explaining the positive correlation with the catalytic activity.
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The development of catalysts with abundant active interfaces for superior low-temperature catalytic CO oxidation is critical to meet increasingly rigorous emission requirements, yet still challenging. Herein, this work reports a PtCo/CoOx/Al2O3 catalyst with PtCo clusters and enriched PtâOâCo interfaces induced by hydrogen spillover from the Pt sites and self-oxidation process in air, exhibiting excellent performance for CO oxidation at low temperatures and humid conditions. The combination of structural characterizations and in situ Fourier transform infrared spectroscopy reveals that the PtCo cluster effectively prevents CO saturation/poisoning on the Pt surface. Additionally, the presence of PtâOâCo interfaces in the PtCo/CoOx/Al2O3 catalyst provides a significant number of active sites for oxygen activation and âOH formation. This facilitates efficient generation of CO2 at ambient temperature by coupling with nearby adsorbed CO molecules, resulting in superior low-temperature activity and long-term stability for CO oxidation under humid conditions. This work provides a facile route toward rationalizing the design of catalysts with more active interfaces for superior low-temperature CO oxidation under humid conditions for practical applications.
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Strain effect in the structurally defective materials can contribute to the catalysis optimization. However, it is challenging to achieve the performance improvement by strain modulation with the help of geometrical structure because strain is spatially dependent. Here, a new class of compressively strained platinum-iridium-metal zigzag-like nanowires (PtIrM ZNWs, M = nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn) and gallium (Ga)) is reported as the efficient alkaline hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) catalysts. Particularly, the optimized PtIrNi ZNWs with 3% compressive strain (cs-PtIrNi ZNWs) can achieve the highest HER/HOR performances among all the catalysts investigate. Their HOR mass and specific activities are 3.2/14.4 and 2.6/32.7 times larger than those of PtIrNi NWs and commercial Pt/C, respectively. Simultaneously, they can exhibit the superior stability and high CO resistance for HOR. Further, experimental and theoretical studies collectively reveal that the compressive strain in cs-PtIrNi ZNWs effectively weakens the adsorption of hydroxyl intermediate and modulates the electronic structure, resulting in the weakened hydrogen binding energy (HBE) and moderate hydroxide binding energy (OHBE), beneficial for the improvement of HOR performance. This work highlights the importance of strain tuning in enhancing Pt-based nanomaterials for hydrogen catalysis and beyond.
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Currently, hydrogen peroxide (H2O2) manufacturing involves an energy-intensive anthraquinone technique that demands expensive solvent extraction and a multistep process with substantial energy consumption. In this work, we synthesized Pd-N4-CO, Pd-S4-NCO, and Pd-N2O2-C single-atom catalysts via an in situ synthesis approach involving heteroatom-rich ligands and activated carbon under mild reaction conditions. It reveals that palladium atoms interact strongly with heteroatom-rich ligands, which provide well-defined and uniform active sites for oxygen (O2) electrochemically reduced to hydrogen peroxide. Interestingly, the Pd-N4-CO electrocatalyst shows excellent performance for the electrocatalytic reduction of O2 to H2O2 via a two-electron transfer process in a base electrolyte, exhibiting a negligible amount of onset overpotential and >95% selectivity within a wide range of applied potentials. The electrocatalysts based on the activity and selectivity toward 2e- ORR follow the order Pd-N4-CO > Pd-N2O2-C > Pd-S4-NCO in agreement with the pull-push mechanism, which is the Pd center strongly coordinated with high electronegativity donor atoms (N and O atoms) and weakly coordinated with the intermediate *OOH to excellent selectivity and sustainable production of H2O2. According to density functional theory, Pd-N4 is the active site for selectivity toward H2O2 generation. This work provides an emerging technique for designing high-performance H2O2 electrosynthesis catalysts and the rational integration of several active sites for green and sustainable chemical synthesis via electrochemical processes.