Discovery of Self-Assembled 2D Ru/Si Superlattices Boosting Hydrogen Evolution.

2D heterostructuring is a versatile methodology for designing nanoarchitecture catalytic systems that allow for reconstruction and modulation of interfaces and electronic structures. However, catalysts with such structures are extremely scarce due to limited synthetic strategies. Here, a highly ordered 2D Ru/Si/Ru/Si… nano-heterostructures (RSHS) is reported by acid etching of the LaRuSi electride.

Dipole Coupling Accelerated H O Dissociation by Magnesium-Based Intermetallic Catalysts.

The water (H O) dissociation is critical for various H O-associated reactions, including water gas shift, hydrogen evolution reaction and hydrolysis corrosion. While the d-band center concept offers a catalyst design guideline for H O activation, it cannot be applied to intermetallic or main group elements-based systems because Coulomb interaction was not considered. Herein, using hydrolysis corrosion of Mg as an example, we illustrate the critical role of the dipole of the intermetallic catalysts for H O dissociation.

Multiple reaction pathway on alkaline earth imide supported catalysts for efficient ammonia synthesis.

The tunability of reaction pathways is required for exploring efficient and low cost catalysts for ammonia synthesis. There is an obstacle by the limitations arising from scaling relation for this purpose. Here, we demonstrate that the alkali earth imides (AeNH) combined with transition metal (TM = Fe, Co and Ni) catalysts can overcome this difficulty by utilizing functionalities arising from concerted role of active defects on the support surface and loaded transition metals.

Topological insulator as an efficient catalyst for oxidative carbonylation of amines.

Topological materials have received much attention because of their robust topological surface states, which can be potentially applied in electronics and catalysis. Here, we show that the topological insulator bismuth selenide functions as an efficient catalyst for the oxidative carbonylation of amines with carbon monoxide and dioxygen to synthesize urea derivatives. For example, the carbonylation of butylamine can be completed over bismuth selenide nanoparticle catalyst in 4 hours at 20°C with a yield of 99%, whereas most noble metal-based catalysts do not function at such a low temperature.

Intermetallic Copper-Based Electride Catalyst with High Activity for C-H Oxidation and Cycloaddition of CO into Epoxides.

Inorganic electrides have been proved to be efficient hosts for incorporating transition metals, which can effectively act as active sites giving an outstanding catalytic performance. Here, it is demonstrated that a reusable and recyclable (for more than 7 times) copper-based intermetallic electride catalyst (LaCu Si ), in which the Cu sites activated by anionic electrons with low-work function are uniformly dispersed in the lattice framework, shows vast potential for the selective C-H oxidation of industrially important hydrocarbons and cycloaddition of CO with epoxide. This leads to the production of value-added cyclic carbonates under mild reaction conditions.

First-Principles Study of Three-Dimensional Electrides Containing One-Dimensional [BaN] Chains.

Electrides, a unique type of compound where electrons act as anions, have a high electron mobility and a low work function, which makes them promising for applications in electronic devices and high-performance catalysts. The discovery of novel electrides and the expansion of the electride family have great significance for their promising applications. Herein, we reported four three-dimensional (3D) electrides by coupling crystal structure database searches and first-principles electronic structure analysis.

Dissociative and Associative Concerted Mechanism for Ammonia Synthesis over Co-Based Catalyst.

The current catalytic reaction mechanism for ammonia synthesis relies on either dissociative or associative routes, in which adsorbed N dissociates directly or is hydrogenated step-by-step until it is broken upon the release of NH 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 N can be activated on both Co metal and the nitride support, which leads to superior low-temperature catalytic performance.

Contribution of Nitrogen Vacancies to Ammonia Synthesis over Metal Nitride Catalysts.

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 for ammonia synthesis. Here, we propose a general rule for the design of nitride-based catalysts for ammonia synthesis, in which the nitrogen vacancy formation energy () dominates the catalytic performance.

Vacancy-enabled N activation for ammonia synthesis on an Ni-loaded catalyst.

Ammonia (NH) is pivotal to the fertilizer industry and one of the most commonly produced chemicals. The direct use of atmospheric nitrogen (N) had been challenging, owing to its large bond energy (945 kilojoules per mole), 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.

Stable single platinum atoms trapped in sub-nanometer cavities in 12CaO·7AlO for chemoselective hydrogenation of nitroarenes.

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·7AlO (C12A7) crystals through theoretical prediction and experimental process.

Palladium-bearing intermetallic electride as an efficient and stable catalyst for Suzuki cross-coupling reactions.

Suzuki cross-coupling reactions catalyzed by palladium are powerful tools for the synthesis of functional organic compounds. Excellent catalytic activity and stability require negatively charged Pd species and the avoidance of metal leaching or clustering in a heterogeneous system. Here we report a Pd-based electride material, YPd, in which active Pd atoms are incorporated in a lattice together with Y.

Discovery of hexagonal ternary phase TiInB and its evolution to layered boride TiB.

MAX phases are a large family of compounds that have been limited, so far, to carbides and nitrides. Here we report the prediction of a compound, TiInB, a stable boron-based ternary phase in the Ti-In-B system, using a computational structure search strategy. This predicted TiInB compound is successfully synthesized using a solid-state reaction route and its space group is confirmed as P[Formula: see text]m2 (No.

Copper-Based Intermetallic Electride Catalyst for Chemoselective Hydrogenation Reactions.

The development of transition metal intermetallic compounds, in which active sites are incorporated in lattice frameworks, has great potential for modulating the local structure and the electronic properties of active sites, and enhancing the catalytic activity and stability. Here we report that a new copper-based intermetallic electride catalyst, LaCuSi, in which Cu sites activated by anionic electrons with low work function are atomically dispersed in the lattice framework and affords selective hydrogenation of nitroarenes with above 40-times higher turnover frequencies (TOFs up to 5084 h) than well-studied metal-loaded catalysts. Kinetic analysis utilizing isotope effect reveals that the cleavage of the H-H bond is the rate-determining step.

Rationally designed n-n heterojunction with highly efficient solar hydrogen evolution.

In most of the reported n-n heterojunction photocatalysts, both the conduction and valence bands of one semiconductor are more negative than those of the other semiconductor. In this work, we designed and synthesized a novel n-n heterojunction photocatalyst, namely CdS-ZnWO4 heterojunctions, in which ZnWO4 has more negative conduction band and more positive valence band than those of CdS. The hydrogen evolution rate of CdS-30 mol %-ZnWO4 reaches 31.

Cube-in-cube hollow Cu9 S5 nanostructures with enhanced photocatalytic activities in solar H2 evolution.

Hydrogen produced from water under solar energy is an ideal clean energy source, and the efficiency of hydrogen production usually depends on the catalytic systems based on new compounds and/or a unique nanostructure. Herein, well-defined cube-in-cube hollow Cu9 S5 nanostructures have been successfully prepared with Cu2 O nanocubes and CS2 as precursors, and single-shell hollow Cu9 S5 nanocubes could be obtained by replacing CS2 with Na2 S. The formation mechanism of cube-in-cube hollow nanostructures has been proposed based on the Kirkendell effect and an outward self-assembly process.

Strongly veined carbon nanoleaves as a highly efficient metal-free electrocatalyst.

Effective integration of one-dimensional carbon nanofibers (CNF) and two-dimensional carbon sheets into three-dimensional (3D) conductive frameworks is essential for their practical applications as electrode materials. Herein, a novel "vein-leaf"-type 3D complex of carbon nanofibers with nitrogen-doped graphene (NG) was prepared through a simple thermal condensation of urea and bacterial cellulose. During the formation of the 3D complex CNF@NG, the graphene species was tethered to CNF via carbon-carbon bonds.

In situ catalytic growth of large-area multilayered graphene/MoS2 heterostructures.

Stacking various two-dimensional atomic crystals on top of each other is a feasible approach to create unique multilayered heterostructures with desired properties. Herein for the first time, we present a controlled preparation of large-area graphene/MoS2 heterostructures via a simple heating procedure on Mo-oleate complex coated sodium sulfate under N2 atmosphere. Through a direct in situ catalytic reaction, graphene layer has been uniformly grown on the MoS2 film formed by the reaction of Mo species with Species, which is from the carbothermal reduction of sodium sulfate.

The crystallinity effect of mesocrystalline BaZrO3 hollow nanospheres on charge separation for photocatalysis.

Highly crystalline mesocrystalline BaZrO3 hollow nanospheres offered higher photocatalytic activities. It is found that the highly crystalline sample can function as a "highway" for electron transport with less grain boundaries, resulting in better charge separation and thus photocatalytic performance.