An Rh(4)Ni alloy nanocatalyst exhibits highly-efficient performance in dehydrogenation of aqueous hydrazine borane. The hydrogen selectivity reaches almost 100%. More interestingly, catalyzed by the ...Rh(4)Ni nanocatalyst, the dehydrogenation of aqueous hydrazine borane is not simply divided into two steps.
Homonuclear dual-atomic catalysts showcase unique electronic modulation due to their dual metal centres, providing new direction in development of efficient catalysts for CO
electroreduction. This ...article highlights a few cutting-edge homonuclear dual-atomic catalysts, focusing on their inherent advantages in efficient and selective CO
electroreduction, to spotlight the potential application of dual-atomic catalysts in CO
electroreduction.
SignificanceThe photosensitizer is one of the important components in the photocatalytic system. Molecular photosensitizers have well-defined structures, which is beneficial in revealing the ...catalysis mechanism and helpful for further structural design and performance optimization. However, separation and recycling of the molecular photosensitizers is a great problem. Loading them into/on two/three-dimensional supports through covalent bonds, electrostatic interactions, and supramolecular interactions is a method that enhances their separation and recycling capability. Nonetheless, the structures of the resulting composites are unclear. Thus, the development of highly crystalline heterogeneity methods for molecular photosensitizers, albeit greatly challenging, is meaningful and desirable in photocatalysis, through which heterogeneous photosensitizers with well-defined structures, definite catalysis mechanisms, and good catalytic performance would be expected.
Dual-atom catalysts (DACs) have emerged as efficient electrocatalysts for CO
reduction owing to the synergistic effect between the binary metal sites. However, rationally modulating the electronic ...structure of DACs to optimize the catalytic performance remains a great challenge. Herein, we report the electronic structure modulation of three Ni
DACs (namely, Ni
-N
, Ni
-N
C
and Ni
-N
C
) by the regulation of the coordination environments around the dual-atom Ni
centres. As a result, Ni
-N
C
exhibits significantly improved electrocatalytic activity for CO
reduction, not only better than the corresponding single-atom Ni catalyst (Ni-N
C
), but also higher than Ni
-N
and Ni
-N
C
DACs. Density functional theory (DFT) calculations revealed that the high electrocatalytic activity of Ni
-N
C
for CO
reduction could be attributed to the electronic structure modulation to the Ni centre and the resulted proper binding energies to COOH* and CO* intermediates.
A rare (3,4,5)-connected self-interpenetrated metal-organic framework with an O-atom lined pore surface has been constructed from Zn(II) and H4L (H4L = ...5,5'-(1,3,6,8-tetraoxobenzolmn3,8phenanthroline-2,7(1H,3H,6H,8H)diyl)-diisophthalic acid), which features an unprecedented 1D + 2D → 3D self-interpenetrated array and shows good controlled drug release properties.
A μ(4)-Cl bridged anionic sodalite-type porous metal-organic framework (Et(2)NH(2))(3)(Cu(4)Cl)(3)(TTCA)(8)·26DEF was synthesized, in which Et(2)NH(2)(+) can be exchanged by Li(+) cations. The ...results of gas measurements indicate that Et(2)NH(2)(+) and Li(+) are beneficial for methane and hydrogen storage, respectively.
Currently, the design and construction of an intelligent stimuli-responsive gel system is still a significant challenge. We present here a new gel system from which the formation of heat-set gels, ...conventional gels and irreversible heat-set gels can be achieved in aromatic solvents. This gel system is based on two-component gelators containing a succinamic acid derivative (SAD) and a primary alkyl amine (R-NH2). With the increase of temperature to 85 °C, a rarely reported reversible heat-set gel (gel formation with the increase of temperature) is afforded. Upon addition of fatty acids into two-component gelators, a conventional gel (gel formation with the decrease of temperature) is formed. When the fatty acid is replaced with dicarboxylic acid, a new heat-set gel is generated, which is irreversible and thermally super-stable. X-ray diffraction analysis reveals that the formation of a reversible heat-set gel relies on electrostatic interactions, hydrogen bonds, and hydrophobic interactions. These two-component gelators show a perfect gel system for the formation of diverse gels including heat-set gels, conventional gels and irreversible heat-set gels. The tunable strategy demonstrated in this letter may provide a new way for creation of more functional gels in gel science.
It is common that different crystal facets in metal and metal oxide nanocrystals display different catalytic performances, whereas such phenomena have been rarely documented in metal-organic ...frameworks (MOFs). Herein, we demonstrate for the first time that a nickel metal-organic layer (MOL) exposing rich (100) crystal facets (Ni-MOL-100) shows a much higher photocatalytic CO
-to-CO activity than the one exposing rich (010) crystal facets (Ni-MOL-010) and its bulky counterpart (bulky Ni-MOF), with a catalytic activity up to 2.5 and 4.6 times more active than Ni-MOL-010 and bulky Ni-MOF, respectively. Theoretical studies reveal that the two coordinatively unsaturated Ni
ions with a close distance of 3.50 Å on the surface of Ni-MOL-100 enables synergistic catalysis, leading to more favorable energetics in CO
reduction than that of Ni-MOL-010.
The reactions of Zn(NO3)2·6H2O with mixed ligands of 5-amino-tetrazole (Hatz) and l,2,4,5-benzenetetracarboxylic acid (H4btec) under hydro(solvo)thermal conditions, gave two three-dimensional (3D) ...porous metal-organic frameworks (MOFs) of {Zn3(atz)2(btec)(DMF)2·DMF·2H2O}n (1) and Zn2(Hprz)(atz)(btec)(H2O)n (2) in the absence and presence of piperazine (prz), respectively. 1 and 2 were characterized by infrared spectra (IR), elemental analyses (EA) and single-crystal/powder X-ray diffraction. In 1, the adjacent 1D Zn3(btec)n2n+ chains are linked together by atz− ligands to form a 3D porous MOF with 1D tetragonal channels filled with coordinated and guest DMF, and lattice water molecules. In 2, the adjacent 2D Zn2(btec)n wavelike sheets are pillared through atz− ligands to generate a 3D layered-pillared porous MOF with 1D open channels, which are occupied by coordinated Hprz+ cations and coordinated water molecules. Additionally, thermal stabilities and photoluminescent properties of both compounds in the solid-state at room temperature have been investigated and discussed in detail.
Two new MOFs constructed from Zn(II) salts with mixed ligands of 5-amino-tetrazole and l,2,4,5-benzenetetracarboxylic acid were synthesized under different reaction conditions. Structural diversities indicate that the reaction solvent system or the presence of organic base play crucial roles in modulating structures of these compounds. And more, their thermal stability and luminescence are also discussed. Display omitted
•Two new Zn(II) MOFs based on mixed ligands were synthesized.•The two Zn(II) MOFs exhibit different structural motifs.•The two Zn(II) MOFs are photoluminscent in the solid state at room temperature.
Using solar energy to convert CO2 into valuable fuels or chemicals offers a powerful solution to urgent energy and environmental problems. However, the development of efficient and selective ...catalysts remains a considerable scientific challenge. To address this, catalytically active CoII centers can be anchored into the porous matrix of metal–organic frameworks (MOFs) by utilizing a robust Zr‐based MOF (Zr‐DMBD) functionalized with freestanding thiol groups to enable efficient post‐synthetic metal insertion. The thus‐prepared Zr‐DMBD−Co MOF solids are modified by well‐defined Co–thiolate units and have the capability of photocatalytically converting CO2 into CO with high efficiency and selectivity under visible‐light irradiation in a water‐containing system. The turnover number and CO selectivity reach as high as 97 941 and 98 %, respectively.
Anchors aweigh: Catalytically active CoII centers can be anchored into the porous matrix of metal–organic frameworks (MOFs) by utilizing a robust Zr‐based MOF functionalized with freestanding thiol groups to enable efficient post‐synthetic metal insertion. The thus‐prepared solids photocatalytically convert CO2 into CO with high efficiency and selectivity under visible‐light irradiation in a water‐containing system.
