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A multistep electron transfer process is realized over C12A7:e− electride composite material. The graphene promotes electron transfer from C12A7:e− through surface Pd to the aryl halide substrates, affording a series of cross-coupling reactions.

Thin-film transistors based on amorphous oxide semiconductors could be used to create low-cost backplane technology for large flat-panel displays. However, a trade-off between mobility and stability has limited the ability of such devices to replace current polycrystalline silicon technologies. Here we show that the sensitivity of amorphous oxide semiconductors to externally introduced impurities and defects is determined by the location of the conduction-band minimum and the relevant doping ability. Using bilayer-structured thin-film transistors, we identify the exact charge-trapping position under bias stress, which shows that the Fermi-level shift in the active layer can occur via electron donation from carbon-monoxide-related impurities. This mechanism is highly dependent on the location of the conduction-band minimum and explains why carbon-monoxide-related impurities greatly affect the stability of high-mobility indium tin zinc oxide transistors but not that of low-mobility indium gallium zinc oxide transistors. Based on these insights, we develop indium tin zinc oxide transistors with mobilities of 70 cm2 (V s)–1 and low threshold voltage shifts of –0.02 V and 0.12 V under negative- and positive-bias temperature stress, respectively. By understanding the origins of instability in high-mobility amorphous oxide transistors, ultrastable thin-film transistors with mobilities of 70 cm2 (V s)–1 can be fabricated.

While using hydride precursors, such as TiH2, can promote the formation of some MAX phases, the mechanism for this stabilization effect by hydrogen has been unsolved. Herein, we report a facile synthesis method of Ti2AC (A = Zn, Al, In, and Ga) MAX phases using hydrogen as the phase stabilizer at their crystallographic voids. DFT calculations revealed that hydrogen could be incorporated in the center of the Ti3A (A = Zn, Al, Ga, and In) cages of Ti2AC MAX phases. The hydrogen is accommodated as an anion as a result of electron transfer from the surrounding Ti and A to H, leading to the stabilized state through Coulomb interaction between (Ti3A)δ+ and H-. Consequently, high-purity Ti2AC (A = Zn, Al, Ga, and In) was directly synthesized under pressure-less and milder temperature conditions by simply employing TiH2 as the precursor. These findings indicate that utilizing hydrogen could be one of the experimental parameters to facilitate the formation of materials having crystallographic voids.

Metal nitride complexes have recently been proposed as an efficient noble-metal-free catalyst for ammonia synthesis utilizing a dual active site concept. However, their high sensitivity to air and moisture has restricted potential applications. We report that their chemical sensitivity can be improved by introducing Al into the LaN lattice, thereby forming La-Al metallic bonds (La-Al-N). The catalytic activity and mechanism of the resulting TM/La-Al-N (TM=Ni, Co) are comparable to the previously reported TM/LaN catalyst. Notably, the catalytic activity did not degrade after exposure to air and moisture. Kinetic analysis and isotopic experiment showed that La-Al-N is responsible for N

We present heavily H

Ammonia is one of the most important industrial intermediates due to the mass-demand for the production of various chemicals. Since the development of the Haber–Bosch process, most ammonia producti...

The Suzuki cross-coupling reaction, which is generally catalyzed by Pd-based materials, is a practical approach to create C–C bonds. Although heterogeneous catalysts, including metal-loaded and int...

Ammonia (NH3) is pivotal to the fertilizer industry and one of the most commonly produced chemicals1. The direct use of atmospheric nitrogen (N2) had been challenging, owing to its large bond energy (945 kilojoules per mole)2,3, until the development of the Haber–Bosch process. Subsequently, many strategies have been explored to reduce the activation barrier of the N≡N bond and make the process more efficient. These include using alkali and alkaline earth metal oxides as promoters to boost the performance of traditional iron- and ruthenium-based catalysts4–6 via electron transfer from the promoters to the antibonding bonds of N2 through transition metals7,8. An electride support further lowers the activation barrier because its low work function and high electron density enhance electron transfer to transition metals9,10. This strategy has facilitated ammonia synthesis from N2 dissociation11 and enabled catalytic operation under mild conditions; however, it requires the use of ruthenium, which is expensive. Alternatively, it has been shown that nitrides containing surface nitrogen vacancies can activate N2 (refs. 12–15). Here we report that nickel-loaded lanthanum nitride (LaN) enables stable and highly efficient ammonia synthesis, owing to a dual-site mechanism that avoids commonly encountered scaling relations. Kinetic and isotope-labelling experiments, as well as density functional theory calculations, confirm that nitrogen vacancies are generated on LaN with low formation energy, and efficiently bind and activate N2. In addition, the nickel metal loaded onto the nitride dissociates H2. The use of distinct sites for activating the two reactants, and the synergy between them, results in the nickel-loaded LaN catalyst exhibiting an activity that far exceeds that of more conventional cobalt- and nickel-based catalysts, and that is comparable to that of ruthenium-based catalysts. Our results illustrate the potential of using vacancy sites in reaction cycles, and introduce a design concept for catalysts for ammonia synthesis, using naturally abundant elements. Ammonia is synthesized using a dual-site approach, whereby nitrogen vacancies on LaN activate N2, which then reacts with hydrogen atoms produced over the Ni metal to give ammonia.

Efficient ammonia synthesis and decomposition processes under mild conditions are important to meet the expanding demand in major applications of ammonia as the energy carrier and to provide feedst...

Single-atom catalysts (SACs) have attracted significant attention because they exhibit unique catalytic performance due to their ideal structure. However, maintaining atomically dispersed metal under high temperature, while achieving high catalytic activity remains a formidable challenge. In this work, we stabilize single platinum atoms within sub-nanometer surface cavities in well-defined 12CaO·7Al2O3 (C12A7) crystals through theoretical prediction and experimental process. This approach utilizes the interaction of isolated metal anions with the positively charged surface cavities of C12A7, which allows for severe reduction conditions up to 600 °C. The resulting catalyst is stable and highly active toward the selective hydrogenation of nitroarenes with a much higher turnover frequency (up to 25772 h−1) than well-studied Pt-based catalysts. The high activity and selectivity result from the formation of stable trapped single Pt atoms, which leads to heterolytic cleavage of hydrogen molecules in a reaction that involves the nitro group being selectively adsorbed on C12A7 surface., Stabilize the active metal single atoms under harsh conditions is critical for the development of single atom catalysts. Here the authors report a nanoporous crystal, 12CaO·7Al2O3, that can firmly stabilize Pt single atoms in its surface cavities for efficient catalytic hydrogenation of nitroarenes.

While using hydride precursors, such as TiH

Interface-related phenomena have great potential to control the superconducting state in Fe-based superconductors. We propose a comprehensive classification of Fe-pnictide heterointerfaces based on electrostatic principles that allow the prediction of the interface microstructure, in particular, distinguishing between clean heterointerfaces and the formation of interfacial layers. The concept was successfully tested on a novel LnOFeAs/BaFe2As2 (Ln = La, Sm) Fe-pnictide heterostructure. With the addition of different cations/anions, it is possible to produce clean interfaces or interfacial layers. The impact of the microstructure on superconductivity in the Fe-pnictide heterostructures is discussed. A classification of Fe-pnictide heterointerfaces based on electrostatic principles into initially compensated and uncompensated interfaces is proposed and used for tailoring the interfacial microstructure and superconducting properties. We show that the heterointerface between LnOFeAs (Ln = La, Sm) and BaFe2As2 is nonpolar and remains clean and coherent with Co2+ addition. Co-diffusion results in superconductivity across the whole bilayer. In contrast, IFL formation occurs after adding O2−, and superconductivity with a 2D signature develops with time.

Maintaining gate bias stability under negative bias stress (NBS) and positive bias stress (PBS) is a long-standing issue in amorphous oxide semiconductor thin-film transistors (TFTs). The passivation of the channel layer is crucial for improving device stability. We show that amorphous gallium oxide, which possesses appropriate energy levels (lower electron affinity and higher ionization potential) for indium–tin–zinc oxide (ITZO) TFTs, can be etched selectively by tetramethyl ammonium hydroxide-containing developers that enable self-alignment passivation, such as easy contact hole formation during the drain and source lithography processes. The self-aligned passivation process led to a-ITZO TFTs with high mobility (>50 cm2 V−1 s−1) and low subthreshold swing (

In this study, we fabricated light-emitting diodes (LEDs) on glass substrates at a maximum process temperature of 200 °C using amorphous oxide semiconductor (AOS) materials as emission layers. Amorphous gallium oxide films doped with rare-earth elements (Eu, Pr, and Tb) were employed as AOS emission layers, and the LEDs emitted clear red, green, and pink luminescence upon direct-current application even in the ambient environment. Resonance photoelectron spectroscopy revealed the difference in the electronic structure of the films for each rare-earth dopant, suggesting different emission mechanisms, viz., electron–hole recombination and impact excitation. Although it is widely believed that amorphous materials are unsuitable for use as emission layers of LEDs because of their high concentrations of mid-gap states and defects, the developed rare-earth-doped AOS materials show good performance as emission layers. This study provides opportunities for the advancement of flexible display technologies operating in harsh environments.

The current catalytic reaction mechanism for ammonia synthesis relies on either dissociative or associative routes, in which adsorbed N2 dissociates directly or is hydrogenated step-by-step until it is broken upon the release of NH3 through associative adsorption. Here, we propose a concerted mechanism of associative and dissociative routes for ammonia synthesis over a cobalt-loaded nitride catalyst. Isotope exchange experiments reveal that the adsorbed N2 can be activated on both Co metal and the nitride support, which leads to superior low-temperature catalytic performance. The cooperation of the surface low work function (2.6 eV) feature and the formation of surface nitrogen vacancies on the CeN support gives rise to a dual pathway for N2 activation with much reduced activation energy (45 kJ·mol-1) over that of Co-based catalysts reported so far, which results in efficient ammonia synthesis under mild conditions.

Fast ionic conductors have considerable potential to enable technological development for energy storage and conversion. Hydride (H−) ions are a unique species because of their natural abundance, light mass, and large polarizability. Herein, we investigate characteristic H− conduction, i.e., fast ionic conduction controlled by a pre-exponential factor. Oxygen-doped LaH3 (LaH3−2xOx) has an optimum ionic conductivity of 2.6 × 10−2 S cm−1, which to the best of our knowledge is the highest H− conductivity reported to date at intermediate temperatures. With increasing oxygen content, the relatively high activation energy remains unchanged, whereas the pre-exponential factor decreases dramatically. This extraordinarily large pre-exponential factor is explained by introducing temperature-dependent enthalpy, derived from H− trapped by lanthanum ions bonded to oxygen ions. Consequently, light mass and large polarizability of H−, and the framework comprising densely packed H− in LaH3−2xOx are crucial factors that impose significant temperature dependence on the potential energy and implement characteristic fast H− conduction., Hydride ions are promising for energy storage since they are abundant, lightweight, and highly mobile, but ionic conductivity should be improved. Here the authors achieve fast hydride ion conductivity in a mixed-anion compound by tuning oxygen content.

LnNiSi (Ln = La-Nd) comprising a three-dimensional NiSi framework has electrons in the crystallographic cavity space. In the temperature region 473-773 K, it accepts the insertion/de-insertion of hydrogen topotactically without a change in unitcell volume. The insertion of hydrogens into the cavity space is accompanied by a redox reaction with the orbitals of atoms constituting the cavity wall. Having small work functions, such intermetallic electrides exhibit metallic electrical and magnetic properties. Owing to a high electron-donating power and reversible exchange between hydrogen and the electrons, Ru5wt%-loaded LaNiSi powder worked as an efficient catalyst for ammonia synthesis under ambient pressure.

Cobalt is well-known as an active component of heterogeneous solid catalysts or metal-complexes for the reduction of dinitrogen into ammonia. However, the activity of bare Co metal itself is not hi...

Ruthenium (Ru) loaded catalysts are of significant interest for ammonia synthesis under mild reaction conditions. The B5 sites have been reported as the active sites for ammonia formation, i.e., Ru with other coordinations were inactive, which has limited the utilization efficiency of Ru metal. The implantation of Ru into intermetallic compounds is considered to be a promising approach to tune the catalytic activity and utilization efficiency of Ru. Here we report an acid-durable electride, LnRuSi (Ln = La, Ce, Pr and Nd), as a B5-site-free Ru catalyst. The active Ru plane with a negative charge is selectively exposed by chemical etching using disodium dihydrogen ethylenediaminetetraacetate (EDTA-2Na) acid, which leads to 2–4-fold enhancement in the ammonia formation rate compared with that of the original catalyst. The turnover frequency (TOF) of LnRuSi is estimated to be approximately 0.06 s−1, which is 600 times higher than that of pure Ru powder. Density functional theory (DFT) calculations revealed that the dissociation of N2 occurs easily on the exposed Ru plane of LaRuSi. This systematic study provides firm evidence that layered Ru with a negative charge in LnRuSi is a new type of active site that differs significantly from B5 sites.

Recently, an "interlayer" has been often adopted in organic-inorganic hybrid perovskite light-emitting diodes (PeLEDs). The term "interlayer" infers that the layer function is not clear, but it improves electroluminescence (EL) performance. In this respect, it is of interest to determine the exact role of the interlayer and how it works in PeLEDs. In this study, the interlayer is determined to play a crucial role in suppressing the chemical reaction between the metal oxide and hybrid perovskite layers. Nevertheless, the use of an interlayer, a wide gap insulator, does not guarantee the best PeLED performance because it hinders charge injection into the emission layer. Here, a method is proposed that does not apply an "interlayer" but enables simultaneous attainment of high EL performance and outstanding device stability. 18-crown 6-ether (18C6) additive (2.5 mg mL

3D-2D structural phase transition is artificially induced to invoke giant electronic modulation in nonequilibrium (Pb1−xSnx)Se., Material properties depend largely on the dimensionality of the crystal structures and the associated electronic structures. If the crystal-structure dimensionality can be switched reversibly in the same material, then a drastic property change may be controllable. Here, we propose a design route for a direct three-dimensional (3D) to 2D structural phase transition, demonstrating an example in (Pb1−xSnx)Se alloy system, where Pb2+ and Sn2+ have similar ns2 pseudo-closed shell configurations, but the former stabilizes the 3D rock-salt-type structure while the latter a 2D layered structure. However, this system has no direct phase boundary between these crystal structures under thermal equilibrium. We succeeded in inducing the direct 3D-2D structural phase transition in (Pb1−xSnx)Se alloy epitaxial films by using a nonequilibrium growth technique. Reversible giant electronic property change was attained at x ~ 0.5 originating in the abrupt band structure switch from gapless Dirac-like state to semiconducting state.

Ammonia is one of the most important feedstocks for the production of fertilizer and as a potential energy carrier. Nitride compounds such as LaN have recently attracted considerable attention due to their nitrogen vacancy sites that can activate N

Vacancies are prevalent and versatile in solid-state physics and materials science. The role of vacancies in strongly correlated materials, however, remains uncultivated until now. Here, we report the discovery of an unprecedented vacancy state forming an extended buckled-honeycomb-vacancy (BHV) ordering in Ir$_{16}$Sb$_{18}$. Superconductivity emerges by suppressing the BHV ordering through squeezing of extra Ir atoms into the vacancies or isovalent Rh substitution. The phase diagram on vacancy ordering reveals the superconductivity competes with the BHV ordering. Further theoretical calculations suggest that this ordering originates from a synergistic effect of the vacancy formation energy and Fermi surface nesting with a wave vector of (1/3, 1/3, 0). The buckled structure breaks the crystal inversion symmetry and can mostly suppress the density of states near the Fermi level. The peculiarities of BHV ordering highlight the importance of "correlated vacancies" and may serve as a paradigm for exploring other non-trivial excitations and quantum criticality., 38 pages, 24 figures, 3 tables

We report the successful synthesis of LaCu0.67Si1.33 and Y5Si3 electride nanoparticles (NPs) using the Ar/H2 arc evaporation technique. The obtained particle sizes are 10–50 nm in diameter, and their surface areas are enhanced by orders of magnitude compared with hand-milled samples. Their catalytic performances were indeed improved by a factor of 60 for the hydrogenation of nitrobenzene (LaCu0.67Si1.33) and 3 for ammonia synthesis (Ru-loaded Y5Si3). This marked difference in the enhancement of catalytic activities between each system can be attributed to the geometric structure of active sites. These results show that the Ar/H2 arc evaporation technique offers wide versatility for the preparation of rare-earth-based electride NPs with enhanced catalytic activities.

The creation of metal catalysts with highly active surfaces is pivotal to meeting the strong economic demand of the chemical industry., The creation of metal catalysts with highly active surfaces is pivotal to meeting the strong economic demand of the chemical industry. Specific flat-shaped pristine fcc ruthenium nanoparticles having a large fraction of atomically active {111} facets exposed on their flat surfaces have been developed that act as a highly selective and reusable heterogeneous catalyst for the production of various primary amines at exceedingly high reaction rates by the low temperature reductive amination of carbonyl compounds. The high performance of the catalyst is attributed to the large fraction of metallic Ru serving as active sites with weak electron donating ability that prevail on the surface exposed {111} facets of flat-shaped fcc Ru nanoparticles. This catalyst exhibits a highest turnover frequency (TOF) of ca. 1850 h–1 for a model reductive amination of biomass derived furfural to furfurylamine and provides a reaction rate approximately six times higher than that of an efficient and selective support catalyst of Ru-deposited Nb2O5 (TOF: ca. 310 h–1).

Ammonia decomposition is an important technology for extracting hydrogen from ammonia toward the realization of a hydrogen economy. Herein, it is reported that large oblate hemispheroidal Ru particles on Ca(NH2 )2 function as efficient catalysts for ammonia decomposition. The turnover frequency of Ru/Ca(NH2 )2 increased by two orders of magnitude when the Ru particle size was increased from 1.5 to 8.4 nm. More than 90 % ammonia decomposition was achieved over Ru/Ca(NH2 )2 with large oblate hemispheroidal Ru particles at 360 °C, which is comparable to that of alkali-promoted Ru catalysts with small Ru particle sizes. XAFS analyses revealed that Ru particles are immobilized on Ca(NH2 )2 by Ru-N bonds formed at the metal/support interface, which lead to oblate hemispheroidal Ru particles. Such a strong metal-support interaction in Ru/Ca(NH2 )2 is also substantiated by DFT calculations. The high activity of Ru/Ca(NH2 )2 with large Ru particles primarily originates from the shape and appropriate size of the Ru particles with a high density of active sites rather than the electron-donating ability of Ca(NH2 )2 .

A low-temperature ammonia synthesis process is required for on-site synthesis. Barium-doped calcium amide (Ba-Ca(NH2 )2 ) enhances the efficacy of ammonia synthesis mediated by Ru and Co by 2 orders of magnitude more than that of a conventional Ru catalyst at temperatures below 300 °C. Furthermore, the presented catalysts are superior to the wustite-based Fe catalyst, which is known as a highly active industrial catalyst at low temperatures and pressures. Nanosized Ru-Ba core-shell structures are self-organized on the Ba-Ca(NH2 )2 support during H2 pretreatment, and the support material is simultaneously converted into a mesoporous structure with a high surface area (>100 m2 g-1 ). These self-organized nanostructures account for the high catalytic performance in low-temperature ammonia synthesis.

Key functions for the stability and activity of Ru catalysts for ammonia synthesis were examined by x-ray absorption fine structure (XAFS) experiments. Ru K-edge XAFS measurements were carried out for two Ru catalysts, Ru/Ca2NH and Ru/CaNH, which include N atoms in the supports. The stable Ru-N bond was observed in the Ru/Ca2NH catalyst, but not in the Ru/CaNH catalyst, which was also supported by theoretical calculations in terms of Ru--anion bond strength. The bond observed in the Ru/Ca2NH works to anchor the Ru nanoparticles to the Ca2NH support, and the activity has been maintained. Formation of anchoring bonds between catalyst particles and supports is essential to create highly active and long lasting catalysts.

Poisoning is defined as deactivation by strong adsorption of, usually, impurities on active sites, which is a serious problem in many important catalytic processes. For example, the activity of ruthenium (Ru) catalyst is significantly degraded by chlorine in ammonia synthesis due to its electron-withdrawing property. Here we demonstrate that 12CaO·7Al₂O₃ with subnanometer-sized cages prevents the poisoning of Ru catalyst by chlorine ions in ammonia synthesis. Conventional supported Ru catalysts exhibit negligibly small activity when a tiny amount of chlorine ions remain on the catalyst surface. In contrast, the catalytic activity of Ru/C12A7 is not influenced by chlorine ions even though the amount of chlorine in Ru/C12A7 is one order of magnitude higher than that of the conventional Ru catalysts. The chlorine resistance of Ru/C12A7 is attributed to the unique anion-exchange properties of C12A7; i.e., the chlorine ions are preferentially trapped in the positively charged sub-nanometer-sized cages of C12A7 instead of OH¯ ions under ammonia synthesis conditions.

Ammonia (NH

Amorphous InGaZnO

High-critical-temperature $({T}_{\mathrm{c}})$ superconductivity at 48 K is reported for hydrogen-doped SmFeAsO epitaxial films on MgO single-crystal substrates. The key processes are pulsed laser deposition to grow undoped SmFeAsO epitaxial films and subsequent topotactic chemical reaction using $\mathrm{Ca}{\mathrm{H}}_{2}$ powders under evacuated silica-glass ampule atmosphere. Based on this post-deposition thermal annealing treatment that we have developed, a maximum hydrogen concentration $x=\phantom{\rule{0.16em}{0ex}}\ensuremath{\sim}0.35$ was realized in $\mathrm{SmFeAs}({\mathrm{O}}_{1--x}{\mathrm{H}}_{x})$. Disordered hydrogen substitution at O sites is experimentally confirmed directly by atomic-scale microstructural observations. Magnetization measurement validates the bulk nature of the high-${T}_{\mathrm{c}}$ superconductivity in the films. This method will become an effective and general method to fabricate various high-quality oxyhydride epitaxial films.

We report naturally occurring van der Waals heterostructural single crystals with intrinsic magnetic topological properties., Heterostructures having both magnetism and topology are promising materials for the realization of exotic topological quantum states while challenging in synthesis and engineering. Here, we report natural magnetic van der Waals heterostructures of (MnBi2Te4)m(Bi2Te3)n that exhibit controllable magnetic properties while maintaining their topological surface states. The interlayer antiferromagnetic exchange coupling is gradually weakened as the separation of magnetic layers increases, and an anomalous Hall effect that is well coupled with magnetization and shows ferromagnetic hysteresis was observed below 5 K. The obtained homogeneous heterostructure with atomically sharp interface and intrinsic magnetic properties will be an ideal platform for studying the quantum anomalous Hall effect, axion insulator states, and the topological magnetoelectric effect.

The size of metal particles is a key factor governing the catalytic performance of metal-supported catalysis, and revealing the essential factor controlling the size of metal particles on support materials is crucial for a new guideline in metal-supported catalysts. In this study, we found adsorption and migration energies of a single metal atom on supports are useful for the qualitative prediction of metal particle sizes on supports by means of the first-principles electronic structure calculations of Ru loaded Ca3N2, CaO, CaF2, and Ca2Si and transmission electron microscopy (TEM) measurements. The first-principles calculations revealed that the adsorption and migration energies of a Ru atom on Ca3N2 and Ca2Si are larger than those on CaO and CaF2 and that the energetic trend shows an excellent correspondence with the bond strengths of Ru anions. In accordance with the first-principles calculations, TEM measurements showed that Ru particles sizes on Ca3N2 and Ca2Si are much smaller than those on CaO and ...

The electronic effects induced by the synergy of stable C12A7:e– electride and bimetallic Ru–Fe nanoparticles efficiently control the chemoselective reduction reaction., Controlling the electronic structure of heterogeneous metal catalysts is considered an efficient method to optimize catalytic activity. Here, we introduce a new electronic effect induced by the synergy of a stable electride and bimetallic nanoparticles for a chemoselective reduction reaction. The electride [Ca24Al28O64]4+·(e–)4, with extremely low work function, promotes the superior activity and selectivity of a Ru–Fe nano-alloy for the conversion of α,β-unsaturated aldehydes to unsaturated alcohols in a solvent-free system. The catalyst is easily separable from the product solution and reusable without notable deactivation. Mechanistic studies demonstrate that electron injection from the electride to the Ru–Fe bimetallic nanoparticles promotes H2 dissociation on the highly charged active metal and preferential adsorption of C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 O bonds over C 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 1111111111111111111111111111111111 1111111111111111111111111111111111 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 0000000000000000000000000000000000 Cs bond of the unsaturated aldehydes, to obtain the thermodynamically unfavorable but industrially important product.

Efficient and stable catalysts for ammonia synthesis under mild conditions are required to meet the strong demand for NH3 as an important precursor chemical and hydrogen carrier. Here we report that during ammonia synthesis, flat-shaped Ru nanoparticles with a narrow distribution (2.1 ± 1.0 nm) and self-organized on Ca(NH2)2 exhibit high catalytic performance far exceeding alkali-promoted Ru-based catalysts in yield and turnover frequency (TOF). This catalyst enables continuous NH3 production, even at 473 K under ambient pressure. During ammonia synthesis, Ru nanoparticles are distinctly anchored on the surface of Ca(NH2)2 by strong Ru–N interaction, which leads to the epitaxial growth of Ru on the support surface. The high catalytic performance is due to the formation of high-density flat-shaped Ru nanoparticles and high electron donor ability at the Ru/Ca(NH2)2 interface. The catalytic stability is significantly improved by Ba-doping of Ca(NH2)2, and no degradation was observed after ca. 700 h of operation.