CO2 adsorption isotherms for comparison of the CO2 adsorption behavior of MOFNH2:crystal and MOFNH2:powder at 298 K. XRPD patterns of (a) simulation of single-crystal XRD data of MOFNH2 ash, (b) MOFNH2 ash, (c) MOFNH2 ash after heating at 250 oC, and (d) activated MOF after immersion in water for 24 h (hydrated MOF). e) reactivate the hydrated MOF.
SiO 3 Lithium metasilicate
Filled, adsorption; Blank, desorption.) (b) The CO2 adsorption isotherms of MIL-101 before and after loading PEI at 25 oC. The first step is a fast and kinetically controlled reaction by chemically absorbing CO2 on the surface of the absorbent. Therefore, they used the kinetic model to describe the mechanism of CO2 absorption and the desorption process on Li4SiO4.
The size of n is related to the reaction rate, depending on the rate of crystal formation and growth when n > 1 and the diffusion control when n is about 0.5.36. In this step, the reaction rate depends on the rate of nucleation, which is very short. In this step, diffusion begins to occur, but the reaction rate still depends on the rate of nucleation.
Preparation of MOFNH2:crystal and MOFNH2:powder. The as-synthesized compounds, MOFNH2-ash, were heated under vacuum at 90 oC for 7 hours and then cooled to ambient temperature and refilled with Ar (MOFNH2:crystal), which is the same as MOFNH2. Two MOFs are composed of the two macrocyclic nickel(II) complexes with pendant propyl ([NiLpropyl]2+) and ethylamine ([NiLethylamine]2+) groups as metal building blocks, respectively, and the same organic ligand (BPDC2-) ( Figure 3.1 ). Thermogravimetric analysis (TGA) of MOFNH2 ash and MOFCH3 ash revealed weight loss up to a temperature of ~ 230 oC, which was concurrent with the total weight percentage of the host water molecules (8.6 wt% and 6.6 wt%, respectively) that the void occupied spaces. Figure 3.4) The guest molecules in both structures were removed by evacuating MOFs for 7 hours at 90 oC, resulting in hospitable structures MOFNH2 and MOFCH3.
Reactivation of the hydrated MOF also resulted in the intact structure as shown in Figure 3.14e. As mentioned above, K2CO3 reacts with Li2CO3 leading to the generation of the eutectic mixture. XRPD patterns of the absorber. purple, before CO2 absorption; black, after CO2. adsorption and desorption.).
According to the reaction mechanism by simulation, the first step of CO2 absorption is the effective collision between CO2.
XRPD patterns of the mixture after evaporation of the solvent using LiOH·H2O as lithium precursor before calcination.
Reactivity of CaO derived from nanosized CaCO3 particles through various CO2 capture and release cycles. Enhanced hydrogen production from biomass with in situ carbon dioxide capture using calcium oxide sorbents. Experimental study and atomic level description of adsorption process of CO2 on doped alkaline earth oxides.
Sorption enhanced hydrogen production by steam methane reforming using Li2ZrO3 as sorbent: sorption kinetics and reactor simulation. Synthesis and CO2 capture evaluation of Li2−xKxZrO3 solid solutions and crystal structure of a new lithium-potassium zirconate phase. Carbon dioxide absorption by lithium orthosilicate in a wide range of temperature and carbon dioxide concentrations.
Sorption of CO2 at high temperature and low concentration on Li4SiO4-based sorbents: Study of the effects of silica used and doping method. Template Synthesis and Properties of Square Planar Nickel(II) and Copper(II) Complexes of 14-Membered Macrocyclic Hexaaza Ligands with Different Alkyl Pendant Arms on Uncoordinated Nitrogen. Effect of quartz powder particle size on the synthesis and CO2 sorption properties of Li4SiO4 at high temperature.
Appendix
Introduction
Sodium-ion batteries are considered a promising alternative to next-generation batteries that can replace Li-ion batteries in large-scale energy storage systems and electric vehicles, due to their potential cost advantages due to the natural abundance of Na sources and geographically. limited Li sources.1–6 A variety of electrode materials such as non-graphitic carbon atoms,7–9 alloys (e.g. Sn and Sb),10–13 metal oxides,14–18 and phosphorus19,20 have been shown to exhibit promising properties electrochemical performance as anodes for Na-ion batteries. Recently, some organic compound-based materials, such as conjugated and aromatic compounds containing carbonyl groups or N-heterocycles, have been reported as promising anode materials due to their attractive characteristics such as good electrochemical performance and low cost. Several sodium terephthalate derivatives with amino and bromine groups have been readily synthesized due to the structural diversity of the organic architecture, resulting in controllable redox potential changes through inductive and resonance effects.27 However, only a small number of organic compounds have been explored as electrode materials for rechargeable batteries such as Li- ion and Na-ion batteries.28–37 In particular, only a few organic compounds have been investigated as electrode materials for Na-ion batteries.38–40.
Here, for the first time, we evaluated new bpdc-sodium salts as anodes for Na-ion batteries and elucidated the correlation between the structural properties of organic anodes and their electrochemical properties. Bpdc-sodium salts were obtained by three different synthetic methods: precipitation at low and room temperatures and solvothermal methods. Based on the degree of deprotonation of the carboxylic acid groups (COOH) and the coordination of the water molecules, three different crystal structures were obtained for the bpdc-sodium salts.
The crystal structures were determined and compared using single-crystal X-ray diffraction (XRD) and powder XRD (PXRD) patterns.
PAPER
Experimental section
After completion of the reaction, the solution was filtered and became clear pale yellow. After two days, pale yellow block-shaped single crystals of {Na[Na(H2O)](bpdc)}n (hyd-Na2bpdc) began to form on the surface of the solution. After completion of the reaction, the solution was evaporated and ethanol (20 mL) was added to the filtrate, resulting in white precipitates.
The two solutions were placed in a glass jar and sealed together, and the mixture was heated at 100C for 48 hours. The plate-shaped colorless crystals obtained were recrystallized, briefly washed with methanol and dried in air. Single crystals of hid-Na2bpdc and NaHbpdc coated with Paratone-N oil were mounted on a loop, and the diffraction data were collected with synchrotron radiation (l¼ 0.64999 ˚A at 95 K for hid-Na2bpdc at 99˚9.09. .
The structures of hyd-Na2bpdc and NaHbpdc have been deposited in the CCDC database, reference numbers 944127 and 944128, respectively. The galvanostatic experiments were performed at 30 C, and specific current density of 18.7 mA g1 (ca. 0.1 C) and 20, 3 mA g1 (approx. 0.1 C) was used to evaluate the cycling performances of NaHbpdc and Na2bpdc, respectively. The GITT experiments were performed between 0.1 and 2.5 Vvs.Na/Na + by applying a current corresponding to a C/20 rate in 1 h intervals, separated by a 1 h rest period.
Results and discussion
Na2bpdc showed a different PXRD pattern, indicating that the crystal structure of Na2bpdc was different from that of hyd-Na2bpdc and NaHbpdc. However, the structure of Na2bpdc was found to be the same as that of hyd-Na2bpdc after the coordinating water. 3D network of (a) hyd-Na2bpdc and (b) NaHbpdc; coordination modes of bpdc2 ligands with sodium ions in (c) hyd-Na2bpdc, and (d) NaHbpdc.
The incorporation of water molecules into the structure of Na2bpdc can depend on both the reaction temperature and the reaction rate. The coulombic efficiency of Na2bpdc and NaHbpdc during the first cycle was 81% and 47%, respectively. The speed performance of Na2bpdc and NaHbpdc was also compared, as shown in Fig.
This superior rate performance of Na2bpdc is clearly attributed to the smaller particle size (diffusion length) of Na2bpdc compared to NaHbpdc, as shown in Fig. As shown in the ex situ XRD patterns of the electrodes during cycling (Fig. 9c), broader PXRD peaks were observed after the cycle, indicating that the amorphization of Na2bpdc occurred during. The oxidative peak at 0.6 V corresponds to the oxidative peak of Na2bpdc, as observed in dQ/dV plots of Na2bpdc (Fig. 12b).
Conclusions
This therefore indicates that some of the NaHbpdc was converted to Na2bpdc during cycling. Since the interesting properties of the coordination polymers for practical applications are strongly influenced by their structures [11,12], intensive efforts have been devoted to the design of new architectures for coordination polymers. In this approach, the structural control of the coordination polymers is based on an understanding of the interaction between the host framework and the guest molecules, and of the influence of the guest molecules on the coordination behavior of the metal ions and the organic linker. .
Two-dimensional (2D) coordination polymers provide a good example for demonstrating flexible variation in their structures depending on the amount, as well as the size and shape of intercalated guest molecules. Due to the flexibility of the aliphatic chain of the BuTC4 ligand, the conformation of the BuTC4-in2 ligand is slightly different from that in 1, but it does not affect the entire bilayer structure of 2 (Fig. S2). For this reason, even under careful crystal treatment, the disordered DEF molecules were not properly refined into the X-ray structure of 1, and thus the data were necessarily squeezed.
Consequently, they are attributed to the instability of the DEF molecules in structure1, and DEF molecules were quickly removed from the interlayer spaces, resulting in the coexistence of the dried structure1′ with the original structure 1. The similar but non-identical XRPD patterns revealed , that the dried structure of 1' had the same interlayer spacing as well as the same intralayer structure as compounds 2 and 2' and its layer packing retained the ∙∙∙A-A-A∙∙∙ structure of 1 instead. Suh, A comparison of the H2 sorption capacity of isostructural metal–organic frameworks with and without accessible metal sites: [{Zn2(abtc)(dmf)2}3] and [{Cu2(abtc)(dmf)2}] versus [ {Cu2(abtc)}3], Angew.
