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Elucidating the structure-property relationship is crucial for the design of advanced electrocatalysts towards the production of hydrogen peroxide (H 2 O 2 ). In this work, we theoretically and experimentally discovered that atomically dispersed Lewis acid sites (octahedral M–O species, M = aluminum (Al), gallium (Ga)) regulate the electronic structure of adjacent carbon catalyst sites. Density functional theory calculation predicts that the octahedral M–O with strong Lewis acidity regulates the electronic distribution of the adjacent carbon site and thus optimizes the adsorption and desorption strength of reaction intermediate (*OOH). Experimentally, the optimal catalyst (oxygen-rich carbon with atomically dispersed Al, denoted as O-C(Al)) with the strongest Lewis acidity exhibited excellent onset potential (0.822 and 0.526 V versus reversible hydrogen electrode at 0.1 mA cm −2 H 2 O 2 current in alkaline and neutral media, respectively) and high H 2 O 2 selectivity over a wide voltage range. This study provides a highly efficient and low-cost electrocatalyst for electrochemical H 2 O 2 production. H 2 O 2 production via oxygen reduction offers a renewable approach to obtain an often-used oxidant. Here, authors show the incorporation of Lewis acid sites into carbon-based materials to improve H 2 O 2 electrosynthesis.

High energy density and enhanced rate capability are highly sought-after for supercapacitors in today’s mobile world. In this work, polyaniline/titanium carbide (MXene) (PANI/Ti 3 C 2 T x ) nanohybrid is synthesized through a facile and cost-effective self-assembly of one-dimensional (1D) PANI nanofibers and two-dimensional (2D) Ti 3 C 2 T x nanosheets. PANI/Ti 3 C 2 T x delivers greatly improved specific capacitance, ultrahigh rate capability (67% capacitance retention from 1 to 100 A·g −1 ) as well as good cycle stability. Electrochemical kinetic analysis reveals that PANI/Ti 3 C 2 T x is featured with surface capacitance-dominated process and has a quasi-reversible kinetics at high scan rates, giving rise to an ultrahigh rate capability. By using PANI/Ti 3 C 2 T x as positive electrode, an 1.8 V aqueous asymmetric supercapacitor (ASC) is successfully assembled, showing a maximum energy density of 50.8 Wh·kg −1 (at 0.9 kW·kg −1 ) and a power density of 18 kW·kg −1 (at 26 Wh·kg −1 ). Moreover, an 3.0 V organic ASC is also elaborately fabricated by using PANI/Ti 3 C 2 T x , achieving an ultrahigh energy density of 67.2 Wh·kg −1 (at 1.5 kW·kg −1 ) and a power density of 30 kW·kg −1 (at 26.8 Wh·kg −1 ). The present work not only improves fundamental understanding of the structure-property relationship towards ultrahigh rate capability electrode materials, but also provides valuable guideline for the rational design of high-performance energy storage devices with both high energy and power densities.

Layered double oxides (LDOs) can restore the parent layered double hydroxides (LDHs) structure under hydrous conditions, and this “memory effect” plays a critical role in the applications of LDHs, yet the detailed mechanism is still under debate. Here, we apply a strategy based on ex situ and in situ solid-state NMR spectroscopy to monitor the Mg/Al-LDO structure changes during recovery at the atomic scale. Despite the common belief that aqueous solution is required, we discover that the structure recovery can occur in a virtually solid-state process. Local structural information obtained with NMR spectroscopy shows that the recovery in aqueous solution follows dissolution-recrystallization mechanism, while the solid-state recovery is retro-topotactic, indicating a true “memory effect”. The amount of water is key in determining the interactions of water with oxides, thus the memory effect mechanism. The results also provide a more environmentally friendly and economically feasible LDHs preparation route. The “memory effect” of layered double hydroxides (LDHs) plays a critical role in their applications, yet the details of the mechanism are still under debate. Here authors reveal the nature of the “memory effect” with ex situ and in situ solid-state NMR spectroscopy.

The detailed information on the surface structure and binding sites of oxide nanomaterials is crucial to understand the adsorption and catalytic processes and thus the key to develop better materials for related applications. However, experimental methods to reveal this information remain scarce. Here we show that 17 O solid-state nuclear magnetic resonance (NMR) spectroscopy can be used to identify specific surface sites active for CO 2 adsorption on MgO nanosheets. Two 3-coordinated bare surface oxygen sites, resonating at 39 and 42 ppm, are observed, but only the latter is involved in CO 2 adsorption. Double resonance NMR and density functional theory (DFT) calculations results prove that the difference between the two species is the close proximity to H, and CO 2 does not bind to the oxygen ions with a shorter O···H distance of approx. 3.0 Å. Extensions of this approach to explore adsorption processes on other oxide materials can be readily envisaged. The characterization of the surface structure and binding sites of materials is crucial for designing advanced materials for adsorption processes. Here, the authors use 17 O solid-state nuclear magnetic resonance spectroscopy to identify specific CO 2 adsorption sites on MgO nanosheets.

The hydrogenation of CO 2 or CO to single organic product has received widespread attentions. Here we show a highly efficient and selective catalyst, Mo 3 S 4 @ions-ZSM-5, with molybdenum sulfide clusters ([Mo 3 S 4 ] n+ ) confined in zeolitic cages of ZSM-5 molecular sieve for the reactions. Using continuous fixed bed reactor, for CO 2 hydrogenation to methanol, the catalyst Mo 3 S 4 @NaZSM-5 shows methanol selectivity larger than 98% at 10.2% of carbon dioxide conversion at 180 °C and maintains the catalytic performance without any degeneration during continuous reaction of 1000 h. For CO hydrogenation, the catalyst Mo 3 S 4 @HZSM-5 exhibits a selectivity to C 2 and C 3 hydrocarbons stably larger than 98% in organics at 260 °C. The structure of the catalysts and the mechanism of CO x hydrogenation over the catalysts are fully characterized experimentally and theorectically. Based on the results, we envision that the Mo 3 S 4 @ions-ZSM-5 catalysts display the importance of active clusters surrounded by permeable materials as mesocatalysts for discovery of new reactions. A series of materials containing Mo-S clusters confined in zeolitic cages of ZSM-5 are reported and shown to be efficient for CO 2 or CO hydrogenation with >98% selectivity to methanol, stable over 1000 h, or C 2 and C 3 hydrocarbons, stable over 100 h.

Although complexes with monatomic zero-valent main group centers have been reported, diatomic zero-valent complexes are extremely rare and all previously reported examples were stabilized by either carbene or silylene ligands. Here, we present the isolation of diatomic E(0)-E(0) (E = Sn, Pb) species supported by two [N{CH₂CH₂NP i Pr₂}₃Sn] fragments. The reaction of trilithium salt N{CH 2 CH 2 NLiP i Pr 2 } 3 with SnCl 2 yields complex [N{CH 2 CH 2 NP i Pr 2 } 3 ] 2 Sn 3 ( 1 ) with a Sn 3 chain. The reduction of the mixture of 1 and SnCl 2 with KC 8 produces the catenated Sn 4 chain [N{CH 2 CH 2 NP i Pr 2 } 3 Sn 2 ] 2 ( 2 ), featuring a diatomic Sn(0)-Sn(0) unit. Further reduction of 2 with KC 8 yields the alkali metal ion-bridged complex [N{CH 2 CH 2 NP i Pr 2 } 3 SnK] 2 ( 3 ). Moreover, the reaction of 3 with PbI 2 and KC 8 affords [N{CH 2 CH 2 NP i Pr 2 } 3 SnPb] 2 ( 4 ), which can also be generated by the reaction of KC 8 with PbI 2 and [N{CH 2 CH 2 NP i Pr 2 } 3 SnLi] 2 ( 5 ). Complex 4 features a diatomic Pb(0)-Pb(0) unit, representing a heavy diatomic zero-valent main group complex. The presence of diatomic E(0)-E(0) (E = Sn, Pb) units in complexes 2 and 4 , respectively, is further confirmed by computational studies. Although complexes with monatomic zero-valent main group centers have been reported, diatomic zero-valent complexes are rare, and previously reported examples were stabilized by either carbene or silylene ligands. Here, the authors report the isolation of a diatomic E(0)-E(0) (E = Sn, Pb) species supported by two [N{CH₂CH₂NP i Pr₂}₃Sn] fragments.

The bridging hydride species (Zn-H-Zn) formed via H 2 dissociation on ZnO surface play crucial roles in hydrogenation of unsaturated hydrocarbon to industrial production. Here, we find that the migration of surface hydroxyl in ZnO nanorods to nearby oxygen vacancy can also lead to the formation of this Zn-H-Zn species that are reactive to CO 2 hydrogenation to methanol using solid-state NMR spectroscopy. Below 100 °C, bridging Zn-H-Zn species show no activity toward CO 2 activation, while formate species are formed via the reaction of CO 2 with surface hydroxyl groups. At 150-200 °C, Zn-H-Zn species hydrogenate formate to methoxy species. At 250 °C, methanol is produced and desorbs from the ZnO surface. These results confirm the methanol formation mechanism via formate and methoxy intermediates in the presence of active bridging Zn-H-Zn species. This work reveals a new source of active hydrogen species in ZnO nanorods without introducing H 2 , which is highly significant for heterogeneous hydrogenation reactions. The bridging hydride species (Zn–H–Zn), commonly formed through H₂ dissociation on ZnO surfaces, are essential for hydrogenating unsaturated hydrocarbons. Here, the authors show that surface hydroxyls on ZnO nanorods can migrate to nearby oxygen vacancies and similarly generate reactive Zn–H–Zn species, which they identify by solid-state NMR spectroscopy as active in CO₂ hydrogenation to methanol.

Controllable supply of hydrogen intermediate across a wide pH range is crucial for electroreduction reactions, but is hindered by pH-dependent hydrogen species formation on conventional catalysts. We report a lattice-hydrogen cycling mechanism that dissociates hydrogen intermediate availability from electrolyte pH. By integrating proton-blocking Ru with thermally-hydrogenated H x WO 3 , we create a dynamic hydrogen reservoir, enabling efficient hydrogen supply. In-situ Raman spectroscopy, isotopic labeling, and theoretical simulations reveal the lattice hydrogen in H x WO 3 migrates swiftly to Ru active sites via low-energy-barrier pathways, while consumed hydrogen is spontaneously replenished via proton adsorption (acidic) or water dissociation (alkaline/neutral). Consequently, this catalyst achieves a competitive pH-universal performance for hydrogen evolution reaction, with low overpotentials (125 mV acidic, 142 mV alkaline, 219 mV neutral @1 A cm -2 ) alongside 500-hour stability. Controllable supply of hydrogen during electroreduction reactions on conventional catalysts is hindered by pH-dependent hydrogen species formation. Here the authors present a lattice-hydrogen cycling mechanism that decouples hydrogen intermediate availability from electrolyte pH.

In typical heterogeneous catalytic reactions, catalysts, whether fixed or flowing, maintained their bulk and surface structures as stable as possible. We report here dynamic activation catalysts having continuously generate highly active sites in working, which enables a usually low active Cu/Al 2 O 3 catalyst for CO 2 hydrogenation, showing extraordinary catalytic performances. Using reaction streams in unusually high linear speed to blow and carry the Cu/Al 2 O 3 particulates to collide cyclically with a rigid target, the CO 2 conversion rate is more than three times enhanced at methanol selectivity promoted to 95% from less than 40% and the methanol space-time-yield is six times increased. By experimental and theoretical investigation, the dynamic activation of Cu/Al 2 O 3 is defined as a discrete condensed state with a distorted and elongated lattice, reduced coordination, and abnormal catalytic properties. We envision that continuous research on the dynamical activation catalysts will advance novel methods for promoting catalytic performance and discovering new catalytic reactions. CO₂ hydrogenation on Cu/Al₂O₃ is limited by low activity. Herein, high-velocity gas collisions create transient distorted Cu sites, tripling CO₂ conversion, boosting methanol selectivity to 95 % and increasing the space-time-yield six times.

Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health, especially among immunocompromised populations. Given the intricate problem of dramatic increase in resistance to common biocides, the development of safe and efficient biocide formulated agents to alleviate drug resistance is highly demanding. In this study, Schiff-base ligands were successfully formed on natural biopolymer of epsilon-poly-L-lysine (ε-PL) decorated aldehyde functionalized mesoporous silica SBA-15 (CHO-SBA-15) for the selective coordination of silver ions, which was affirmed by various physicochemical methods. Besides the identified broad-spectrum antibacterial activities, the as-prepared Schiff-base silver nanocomplex (CHO-SBA-15/ε-PL/Ag, CLA-1) exhibited an improved inhibitory effect on infectious pathogen growth typified by Escherichia coli and Staphylococcus aureus in comparison with two control silver complexes without Schiff-base conjugates, SBA-15/ε-PL/Ag and CHO-SBA-15/Ag, respectively. In addition, CLA-1 remarkably inhibited the growth of Mycobacterium tuberculosis due to the excellent antimicrobial activity of silver species. Significantly, CLA-1 kills Candida albicans cells, inhibits biofilm formation, and eliminates preformed biofilms, with no development of resistance during continuous serial passaging. The antifungal activity is connected to disruption of bacterial cell membranes and increased levels of intracellular reactive oxygen species. In mouse models of multidrug-resistant C. albicans infection, CLA-1 exhibited efficient in vivo fungicidal efficacy superior to two antifungal drugs, amphotericin B and fluconazole. Moreover, CLA-1 treatment induces negligible toxicity against normal tissues with safety. Therefore, this study reveals the pivotal role of the molecular design of Schiff-base silver nanocomplex formation on biopolymer surface-functionalized silica mesopores as a green and efficient nanoplatform to tackle infectious microbes.