Hydrazine-Mediated Thermally Assisted Photocatalytic Ammonia Decomposition Over Layered Protonated Perovskites.

Photocatalytic ammonia decomposition offers a sustainable route for hydrogen production, but its development is limited by low catalytic efficiency and poorly understood mechanisms. Here, a protonated layered perovskite, HPrNbO (HPNO), is reported as an efficient catalyst for ammonia decomposition under mild photo-thermal conditions. Upon exposure to NH at elevated temperatures, HPNO promotes the in situ formation and intercalation of hydrazine intermediates within its interlayer galleries, enabled by thermally generated oxygen vacancies and hydrogen bonding.

Dispersed surface Ru ensembles on MgO(111) for catalytic ammonia decomposition.

Ammonia is regarded as an energy vector for hydrogen storage, transport and utilization, which links to usage of renewable energies. However, efficient catalysts for ammonia decomposition and their underlying mechanism yet remain obscure. Here we report that atomically-dispersed Ru atoms on MgO support on its polar (111) facets {denoted as MgO(111)} show the highest rate of ammonia decomposition, as far as we are aware, than all catalysts reported in literature due to the strong metal-support interaction and efficient surface coupling reaction.

Exceptional Hydrogen Diffusion Rate over Ru Nanoparticle-Doped Polar MgO(111) Surface.

Hydrogen (H) conductivity on oxide-based materials is crucially important in fuel cells and related catalysis. Here, this work measures the diffusion rate of H generated from Ru nanoparticles loaded on polar MgO(111) facet particles under H at elevated temperatures without moisture and compares it to conventional nonpolar MgO(110) for the first time by in situ quasielastic neutron scattering (QENS). The QENS reveals an exceptional diffusion rate on the polar facet via a proton (H ) hopping mechanism, which is an order of magnitude superior to that of typical H -conducting oxides.

Structural insight into [Fe-S-Mo] motif in electrochemical reduction of N over Fe-supported molecular MoS.

The catalytic synthesis of NH from the thermodynamically challenging N reduction reaction under mild conditions is currently a significant problem for scientists. Accordingly, herein, we report the development of a nitrogenase-inspired inorganic-based chalcogenide system for the efficient electrochemical conversion of N to NH, which is comprised of the basic structure of [Fe-S-Mo]. This material showed high activity of 8.

Rapid Interchangeable Hydrogen, Hydride, and Proton Species at the Interface of Transition Metal Atom on Oxide Surface.

Hydrogen spillover is the phenomenon where a hydrogen atom, generated from the dissociative chemisorption of dihydrogen on the surface of a metal species, migrates from the metal to the catalytic support. This phenomenon is regarded as a promising avenue for hydrogen storage, yet the atomic mechanism for how the hydrogen atom can be transferred to the support has remained controversial for decades. As a result, the development of catalytic support for such a purpose is only limited to typical reducible oxide materials.

High Loading of Transition Metal Single Atoms on Chalcogenide Catalysts.

Transition metal doped chalcogenides are one of the most important classes of catalysts that have been attracting increasing attention for petrochemical and energy related chemical transformations due to their unique physiochemical properties. For practical applications, achieving maximum atom utilization by homogeneous dispersion of metals on the surface of chalcogenides is essential. Herein, we report a detailed study of a deposition method using thiourea coordinated transition metal complexes.

A rational study on the geometric and electronic properties of single-atom catalysts for enhanced catalytic performance.

We investigate the geometric and electronic properties of single-atom catalysts (SACs) within metal-organic frameworks (MOFs) with respect to electrocatalytic CO2 reduction as a model reaction. A series of mid-to-late 3d transition metals have been immobilised within the microporous cavity of UiO-66-NH2. By employing Rietveld refinement of new-generation synchrotron diffraction, we not only identified the crystallographic and atomic parameters of the SACs that are stabilised with a robust MN(MOF) bonding of ca.

Photocatalytic water splitting by N-TiO on MgO (111) with exceptional quantum efficiencies at elevated temperatures.

Photocatalytic water splitting is attracting enormous interest for the storage of solar energy but no practical method has yet been identified. In the past decades, various systems have been developed but most of them suffer from low activities, a narrow range of absorption and poor quantum efficiencies (Q.E.

Efficient Non-dissociative Activation of Dinitrogen to Ammonia over Lithium-Promoted Ruthenium Nanoparticles at Low Pressure.

There is an exciting possibility to decentralize ammonia synthesis for fertilizer production or energy storage without carbon emission from H obtained from renewables at small units operated at lower pressure. However, no suitable catalyst has yet been developed. Ru catalysts are known to be promoted by heavier alkali dopants.

Self- regeneration of Au/CeO based catalysts with enhanced activity and ultra-stability for acetylene hydrochlorination.

Replacement of Hg with non-toxic Au based catalysts for industrial hydrochlorination of acetylene to vinyl chloride is urgently required. However Au catalysts suffer from progressive deactivation caused by auto-reduction of Au(I) and Au(III) active sites and irreversible aggregation of Au(0) inactive sites. Here we show from synchrotron X-ray absorption, STEM imaging and DFT modelling that the availability of ceria(110) surface renders Au(0)/Au(I) as active pairs.

Zinc-Incorporated Microporous Molecular Sieve for Mild Catalytic Hydrolysis of γ-Valerolactone: A New Selective Route for Biomass Conversion.

γ-Valerolactone (GVL) is regarded as a key platform molecule in the production of fine chemicals such as pentenoic acid (PA) from biomass. Although PA is believed to be the key intermediate in solid-acid-catalyzed reactions of GVL, due to subsequent facile decarboxylation reactions further alkene products are formed. Here, by tailoring the acidity of Brønsted acid sites in an aluminophosphate (AlPO) molecular sieve through incorporation of Zn into the framework, we access a new selective and effective catalyst for GVL conversion to PA.

Transition metal atom doping of the basal plane of MoS monolayer nanosheets for electrochemical hydrogen evolution.

Surface sites of extensively exposed basal planes of MoS monolayer nanosheets, prepared BuLi exfoliation of MoS, have been doped with transition metal atoms for the first time to produce 2D monolayer catalysts used for the electrochemical hydrogen evolution reaction (HER). Their HER activity is significantly higher than the corresponding thin and bulk MoS layers. HAADF-STEM images show direct proof that single transition metal atoms reside at the surface basal sites, which subtly modify the electro-catalytic activity of the monolayer MoS, dependent on their electronic and stereospecific properties.