It is still a great challenge to achieve high selectivity of ethanol in CO2 electroreduction reactions (CO2RR) because of the similar reduction potentials and lower energy barrier of possible other ...C2+ products. Here, we report a MOF‐based supported low‐nuclearity cluster catalysts (LNCCs), synthesized by electrochemical reduction of three‐dimensional (3D) microporous Cu‐based MOF, that achieves a single‐product Faradaic efficiency (FE) of 82.5% at −1.0 V (versus the reversible hydrogen electrode) corresponding to the effective current density is 8.66 mA cm−2. By investigating the relationship between the species of reduction products and the types of catalytic sites, it is confirmed that the multi‐site synergism of Cu LNCCs can increase the C−C coupling effect, and thus achieve high FE of CO2‐to‐ethanol. In addition, density functional theory (DFT) calculation and operando attenuated total reflectance surface‐enhanced infrared absorption spectroscopy further confirmed the reaction path and mechanism of CO2‐to‐EtOH.
In Mn(5-MeOsalen)(Cl)
(dibenzo24crown-8), dibenzo24crown-8 formed a supramolecule
multi-point interactions with the Mn(5-MeOsalen)(Cl) dimer. The dimer was magnetically isolated with
= 4 and weak ...interdimer magnetic interactions. The crystal exhibited single-molecule magnet behaviour with an anisotropic barrier of 26(1) K, which is the highest among the Mn-salen series reported to date.
Molecular ferroelectrics have promising potential as next-generation flexible electronic materials by the advantage of flexibility, structural tunability, and easy processability. However, an ...obstacle in expanding their promising applications is effectively raising the ferroelectric transition temperature (Tc) necessary for practical applications, especially under high-temperature operating conditions. Herein, taking the advantage of a hydroxyl group that could form stronger hydrogen bonds to insert/tune host–guest and guest–guest interactions, we employed the 3-hydroxypyrrolidine cation to construct two new enantiomeric hexagonal perovskite ferroelectrics, (R)-3-OH-(C4H9N)CdCl3 and (S)-3-OH-(C4H9N)CdCl3. Both of them undergo a ferroelectric phase transition from C2221 to P21 with a high Tc of 350 K, which is 110 K and 47 K higher than that of their parent compound (C4H10N)CdCl3 (240 K) and F-substituted analogues (R/S)-3-F-(C4H9N)CdCl3 (303 K), respectively. These findings well demonstrate that, besides the F-substitution strategy, an OH-substitution strategy provides an important and practical way in designing high-Tc ferroelectrics.
It is still a great challenge to achieve high selectivity of ethanol in CO2 electroreduction reactions (CO2RR) because of the similar reduction potentials and lower energy barrier of possible other ...C2+ products. Here, we report a MOF‐based supported low‐nuclearity cluster catalysts (LNCCs), synthesized by electrochemical reduction of three‐dimensional (3D) microporous Cu‐based MOF, that achieves a single‐product Faradaic efficiency (FE) of 82.5% at −1.0 V (versus the reversible hydrogen electrode) corresponding to the effective current density is 8.66 mA cm−2. By investigating the relationship between the species of reduction products and the types of catalytic sites, it is confirmed that the multi‐site synergism of Cu LNCCs can increase the C−C coupling effect, and thus achieve high FE of CO2‐to‐ethanol. In addition, density functional theory (DFT) calculation and operando attenuated total reflectance surface‐enhanced infrared absorption spectroscopy further confirmed the reaction path and mechanism of CO2‐to‐EtOH.
Dielectric switches play an important role in electrical and electronic devices. Here we report a unique class of cage-like hybrid rare-earth perovskites, ( i -PrNHMe 2 ) 2 RbLn(NO 3 ) 6 (Ln = La, ...Ce, Nd or Sm), capable of functioning as temperature-responsive multiple dielectric switches. The strategic incorporation of a conformationally flexible sphere-like guest ( i -PrNHMe 2 ) + cation into the cage-like perovskite framework is in favor of the occurrence of hierarchical guest dynamics accompanied by stepwise phase transitions, leading to a seldom observed multiple dielectric switching of “Low↔High↔Low↔High” upon heating. Furthermore, the utilizing of lanthanide contraction or rare-earth doping allows for fine tuning of the switching temperature. In addition, multiaxial ferroelasticity is found in these perovskites. Overall, this study provides a good approach for the design of temperature-tunable multiple dielectric switches.
Spin-reorientation-induced magnetodielectric coupling effects were discovered in two layered perovskite magnets, C
6
H
5
CH
2
CH
2
NH
3
2
MCl
4
(M = Mn
2+
and Cu
2+
),
via
isothermal ...magnetodielectric measurements on single-crystal samples. Specifically, peak-like dielectric anomalies and spin-flop transitions appeared simultaneously at around ±34 kOe for the canted antiferromagnet (M = Mn
2+
) at below 44.3 K, while a low-field (1 kOe) controlled magnetodielectric effect was observed in the "soft" ferromagnet (M = Cu
2+
) at below 9.5 K. These isothermal magnetodielectric effects are highly reproducible and synchronous with the field-induced magnetization at different temperatures, well confirming the essential role of spin reorientation on inducing magnetodielectric coupling effects. These findings strongly imply that the layered perovskite magnets are new promising organic-inorganic hybrid systems to host magnetodielectric coupling effects.
Spin-reorientation-induced magnetodielectric effects were discovered in two layered perovskite magnets, (C
6
H
5
CH
2
CH
2
NH
3
)
2
MCl
4
(M = Mn
2+
and Cu
2+
),
via
highly reproducible isothermal magnetodielectric measurements on single-crystal samples.
Spin-reorientation-induced magnetodielectric effects were discovered in two layered perovskite magnets, (C
6
H
5
CH
2
CH
2
NH
3
)
2
MCl
4
(M = Mn
2+
and Cu
2+
),
via
highly reproducible isothermal ...magnetodielectric measurements on single-crystal samples.
Spin-reorientation-induced magnetodielectric coupling effects were discovered in two layered perovskite magnets, C
6
H
5
CH
2
CH
2
NH
3
2
MCl
4
(M = Mn
2+
and Cu
2+
),
via
isothermal magnetodielectric measurements on single-crystal samples. Specifically, peak-like dielectric anomalies and spin-flop transitions appeared simultaneously at around ±34 kOe for the canted antiferromagnet (M = Mn
2+
) at below 44.3 K, while a low-field (1 kOe) controlled magnetodielectric effect was observed in the “soft” ferromagnet (M = Cu
2+
) at below 9.5 K. These isothermal magnetodielectric effects are highly reproducible and synchronous with the field-induced magnetization at different temperatures, well confirming the essential role of spin reorientation on inducing magnetodielectric coupling effects. These findings strongly imply that the layered perovskite magnets are new promising organic–inorganic hybrid systems to host magnetodielectric coupling effects.
Two hybrid salts, 2ClBzTPP
2
Ni(i-mnt)
2
(1) and 4ClBzTPP
2
Ni(i-mnt)
2
(2), were obtained in crystalline form by the reaction of disodium iso-maleonitriledithiolate (K
2
(i-mnt)) with nickel(II) ...chloride hexahydrate and 1-(2′-chlorobenzyl)triphenyl-phosphonium or 1-(4′-chlorobenzyl)triphenylphospho-nium bromide (2ClBzTPPBr/4ClBzTPPBr) in methanol. Two salts were characterized by elemental analyses, UV, IR, ESI-MS, molar conductivity, and single-crystal X-ray diffraction. Both salts crystallize in the triclinic space group P-1 and the central Ni(II) ion has a distorted square planar coordination geometry. Lattice stability is provided by weak interactions observed in 1 and 2 such as C-H···S, C-H···Cl, and C-H···Ni hydrogen bonds and π···π or p···π interactions, which results in the forming of a 3D network structure.
Two new ion-pair complexes, based on Ni(i-mnt)
2
2-
(i-mnt = isomaleonitriledithiolate) anion, Bz-4-MePy
2
Ni(i-mnt)
2
(Bz-4- MePy
+
= 1-benzyl-4′-methylpyridinium) (1) and Bz-4-MeQl
2
Ni(i-mnt)
2
...(Bz-4-MeQl
+
= 1-benzyl-4′-methylquinolinium) (2), were obtained and characterized. The most obvious structure feature of 1 and 2 is that the Ni(i-mnt)
2
2-
anions form a 1D chain through C···N or C···C short interactions between the i-mnt ligands, and the Bz-4-MeQl
+
cations of 2 form a 2D structure through the π···π stacking interactions between the aromatic rings. The C-H···N and C-H···Ni hydrogen bonds observed in the anions and cations consolidate the stacking of the molecules and give rise to a 3D network structure.
The residual stress generated in the manufacturing process of inertial platform causes the drift of inertial platform parameters in long-term storage condition.However,the existing temperature ...cycling experiment could not meet the increased repeatability technical requirements of inertial platform parameters.In order to solve this problem,in this paper,firstly the Unigraphics（UG） software and the interface compatibility of ANSYS software are used to establish the inertial platform finite element model.Secondly,the residual stress is loaded into finite element model by ANSYS function editor in the form of surface loads to analyze the efficiency.And then,the generation based on ANSYS simulation inertial platform to accelerate the stability of experiment profile is achieved by the application of the analysis method of orthogonal experimental design and ANSYS thermal-structural coupling.The optimum accelerated stability experiment profile is determined finally,which realizes the rapid,effective release of inertial platform residual stress.The research methodology and conclusion of this paper have great theoretical and practical significance to the production technology of inertial platform.
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