Abstract Although manganese oxide- and graphene-based supercapacitors have been widely studied, their charge storage mechanisms are not yet fully investigated. In this work, we studied the of K-birnassite MnO 2 nanosheets N-doped reduced graphene oxide aerogel (N-rGO ae ) using an in situ X-ray absorption spectroscopy (XAS) electrochemical quart crystal microbalance (EQCM). The oxidation number Mn at electrode is +3.01 0 V vs. SCE for charging process gets oxidized to +3.12 +0.8 then back...

Manganese dioxide (MnO₂) has been widely used as an active material for high-performance supercapacitors due to its high theoretical capacitance, cycling stability, low cost, and environmental friendliness.

The oxygen evolution and reduction reactions (OER ORR, respectively) are important in the field of renewable clean energy, particularly for hydrogen production fuel cells. These applications have so far been limited because high price catalysts energy loss due to overpotentials. Hence, non-precious metal with efficiency toward OER/ORR desirable. In this work, we employ density functional theory (DFT) calculations study on metalloporphyrin halogenated frameworks. free energies reaction...

The initial stage of glycerol conversion over H-ZSM-5 zeolite has been investigated using density functional theory (DFT) calculations on an embedded cluster model consisting 128 tetrahedrally coordinated atoms. It is found that dehydration to acrolein and acetol proceeds favourably via a stepwise mechanism. formation alkoxide species upon the first requires highest activation energy (42.5 kcal mol−1) can be considered as rate determining step reaction. intrinsic energies for are virtually...

Activation of methane has attracted a great deal interest in laboratory chemical synthesis and large-scale industrial processes. We performed density functional theory studies to investigate the C–H bond breaking on Au+ Au2+ ions vacuum inside different types zeolites. The M06-L 6-31G(d,p) basis set were employed as this level had already been shown be reasonably accurate affordable for transition metal systems. investigated four industrially important catalysts, ZSM-5, FAU, FER, MCM-22,...

Superprotonic phase transition in CsHSO4 allows fast protonic conduction, but only at temperatures above the temperature of 141 °C (Tc). Here, we preserve superprotonic conductivity by forming a binary CsHSO4-coordination polymer glass system, showing eutectic melting. Their anhydrous proton conductivities below Tc are least 3 orders magnitude higher than without compromising or need for humidification, reaching 6.3 mS cm-1 180 °C. The also introduces processability to conductor, as its...

We demonstrated the construction of binary phase diagrams coordination polymer crystals by using their reversible solid–liquid transition (melting and crystallization) behaviors. Three types Ag+-based polymers were made origins each diagram formation investigated. All showed eutectic phenomena induced ligand exchange reactions at interface two constituents. Solid solution was observed when we used with similar structures geometries, reaction driven both anion processes. The optimal compounds...

We demonstrate one-pot conversion of CO 2 into amorphous formate-based metal-organic frameworks (MOFs) that form grain-boundary-free monoliths with permanent porosity through hot-pressing. The local coordination geometries metal ions are characterized...

The Baeyer‐Villiger and epoxidation reactions of dihydrocarvone with hydrogen peroxide over zeolite catalysts is investigated using the M06‐L density functional theory. reaction 38T quantum clusters Sn‐, Ti‐, Zr‐, Hf‐beta zeolites thought to proceed via a two‐step mechanism apparent activation energies 5.3, 18.1, ‐1.3, ‐0.9 kcal/mol energy spans 33.6, 40.1, 31.1, 34.8 kcal/mol, respectively. calculated competitive are 11.2, 16.2, 16.4, 15.0 Sn‐beta selectively afforded lactone product owing...

Zr-based MOF has been designed as a versatile adsorbent for the simultaneous removal of both As(III) and Hg(II) species with high adsorption efficiency. The synthesis procedure optimized to maximize density binding sites by introducing defects in Zr clusters incorporating amino functional groups into linkers. accessible result capacities 626.71 mg g-1 4.24 Hg(II), which are among highest reported values. robustness performance was evaluated various media complex matrices, including river...

The new Aurivillius layered perovskite compounds, AgxNa0.5-xBi2.5Nb2O9 (AGBNO), were successfully synthesized using a hydrothermal technique followed by conventional, microwave-assisted, and acid-assisted ion exchange procedures. formation of these compounds was evidenced several techniques. A single-phase crystal structure identified XRD patterns, expanded lattice parameters revealed refinement. Chemical composition verified EDS, XPS, ICP-OES analyses. Bandgap energies remained similar to...

The electrocatalytic reduction of carbon dioxide (CO2ER) is a great challenge within the field energy and environmental research. Competing reactions, including hydrogen evolution reactions (HER) surface oxidation, limit conversion CO2ER at low overpotentials. This because these competing produce intermediates (adsorbed H OH) with chemical bonds similar to those formed in COOH OCHO). Here, we report adsorption free energies competitive H-bonding functionalized metalloporphyrin frameworks...

Zr-based UiO-66 metal–organic framework (MOF) is one of the most studied MOFs with a wide range potential applications. While typically synthesized as microcrystalline solid, we employ particle downsizing strategy to synthesize fluid gel unique rheological properties, which allows solution-based processing sub-100 nm films and enhances electrical conductivity its pristine structure. Film thicknesses ranging from 40 150 could be achieved by controlling spin-coating parameters. The generality...

The melt state of coordination polymer crystals is composed macromolecular-chain assemblies without bond breaking. coordination-polymer-forming liquid provides various morphologies, including spun fibers.

2-D layer type porous coordination polymers containing redox active Fe2+ centers were synthesized. One of the compounds [Fe(isophthalate)(4,4′-bipyridyl)] showed structural flexibility via guest adsorption, and we observed reversible Fe3+ switching by iodine insertion. The composite electric conductivity.

The selective oxidation of carbon monoxide (CO) remains a challenge in many research areas. Here we propose using porous hybrid organic–inorganic frameworks as tunable single-metal site catalysts which can be utilized for the reaction. Low-valent zinc ions were embedded on ZSM-5 zeolite and metal organic framework (MOF) supports to used nonprecious catalysts. Unlike case with ionic compensation between zeolite, linker-functionalized MOFs exhibit delocalized electron residing both linker...

A coordination polymer semiconductor based on tin(<sc>ii</sc>) thiocyanate having high transparency is reported.

Abstract Herein, two deep‐blue emissive molecules ( SAF‐PI and SAF‐DPI ) are designed synthesized using spiro[acridine‐9,9’‐fluorene] as a donor (D) substituted with 2‐(3‐methylphenyl)‐1‐phenyl‐phenanthro[9,10‐d]imidazole an acceptor (A), forming twisted D−A A−D−A structures, respectively. The photophysical studies density functional theory (DFT) calculations reveal that both exhibit hybridized local excited charge transfer (HLCT) characteristics deep blue emission color. They effectively...

Abstract 5‐hydroxylmethylfurfural (HMF) is a bio‐based chemical that can be prepared from natural abundant glucose by using combined Brønsted–Lewis acid catalysts. In this work, Al 3+ catalytic site has been grafted on Brønsted metal–organic frameworks (MOFs) to enhance acidity of MOF catalysts for one‐pot glucose‐to‐HMF transformation. The uniform porous structure zirconium‐based MOFs allows the optimization both strength and density sites in MOF‐based incorporating desired amount at...

Most metal-organic frameworks (MOFs) lack charge mobility, which is crucial for realizing their use in optoelectronic applications. This work proposes the design of a MOF using triarylamine-based ligands (Zr-NBP) as lone pair electron spacer to enhance hole mobility while maintaining its luminescent properties. Zr-NBP has strong fluorescence with good 1.05×10-6 cm2 V-1 s-1 , comparable organic materials used devices. We also employed nanofilm pure phase both non-doped emissive layer and...

Zirconium clusters of UiO-66 have been hydroxylated with NaOH to generate strong binding sites for As(III) species in wastewater treatment. Hydroxylated provides high adsorption capacity over a wide range pH from 1 10 maximum uptake 204 mg g-1, which is significantly enhanced compared those pristine UiO-66, acid-modulated and other adsorbents use treatment processes. The local structure mechanism are determined by extended X-ray absorption fine combined density functional theory calculations.

We developed a new route for synthesis of Cr-based porous coordination polymers (PCPs) with azole ligands and characterized the unique open structures by single-crystal X-ray studies other spectroscopy techniques. Chromium-based PCPs have been prepared from azolate 3,5-dimethyl-1H-pyrazole-4-carboxylic acid (H2dmcpz) 1,4-di(1H-tetrazole-5yl)benzene (H2BDT) solvothermal reactions under an Ar atmosphere. [Cr3O(Hdmcpz)6(DMF)3]⊃DMF (1⊃DMF) is compound that forms hydrogen-bonded network....

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFabrication of ε-Fe2N Catalytic Sites in Porous Carbons Derived from an Iron–Triazolate CrystalYu-ichi FujiwaraYu-ichi FujiwaraFunctional Materials Science Research Laboratories, & Development Headquarters, Lion Corporation, 2-1, Hirai 7-chome, Edogawa-ku, Tokyo 132-0035, JapanDepartment Synthetic Chemistry and Biological Chemistry, Graduate School Engineering, Kyoto University, Katsura, Nishikyo-ku, 615-8510, JapanMore by Yu-ichi Fujiwara,...