Fen Li

High and selective CO2 uptake, H2storage and methanol sensing on the amine-decorated 12-connected MOF CAU-1

The amine-decorated microporous metal–organic framework CAU-1 was readily synthesized and activated using a home-made efficient protocol. It exhibited a high heat of adsorption for CO2, high CO2 uptake capacity, and an impressive selectivity for CO2 over N2. At 273 K and up to 1 atm, CO2 uptake capacity can reach as much as 7.2 mmol g−1. Comparatively, the CH4 and N2 uptakes at 273 K and 1 atm were only 1.34 mmol g−1 and 0.37 mmol g−1, respectively. The CO2/N2 selectivity was 101 : 1 at 273 K. The isosteric heat of adsorption (Qst) for CO2 was ∼48 kJ mol−1 at the onset of adsorption, and it decreases to ∼28 kJ mol−1 at higher CO2 pressures. Furthermore, CAU-1 can adsorb 2.0 wt% and 4.0 wt% hydrogen at 77 K under 1 atm and 30 atm, respectively. The adsorption characteristics of CAU-1 for methanol investigated in situ with a quartz crystal microbalance (QCM), indicated that this particular MOF structure can be used as a highly sensitive sensor for methanol detection such as direct methanol fuel cells.

Mesoporous metal–organic frameworks: design and applications

Metal–organic frameworks (MOFs), which are constructed from the assembly of organic ligands with metal ions or metal clusters, have high potential applications in the fields of gas storage, separations and catalysis. MOFs involving mesopores are considered to have specific performance in such fields. In this mini review, we are mainly focussing on the recent developments in mesoporous MOFs including the design strategies and their most important applications.

Nanosized Cu-MOFs induced by graphene oxide and enhanced gas storage capacity

Various MOFs with tailored nanoporosities have recently been developed as potential storage media for CO2 and H2. The composites based on Cu-BTC and graphene layers were prepared with different percentages of graphene oxide (GO). Through the characterization analyses and gas adsorption experiments, we found that the nanosized and well-dispersed Cu-BTC induced by the incorporation of GO greatly improved the carbon dioxide capture and hydrogen storage performance of the composites. The materials obtained exhibited about a 30% increase in CO2 and H2 storage capacity (from 6.39 mmol g−1 of Cu-BTC to 8.26 mmol g−1 of CG-9 at 273 K and 1 atm for CO2; from 2.81 wt% of Cu-BTC to 3.58 wt% of CG-9 at 77 K and 42 atm for H2). Finally, the CO2/CH4 and CO2/N2 selectivities were calculated according to single-component gas sorption experiment data.

Thermodynamic investigation of room temperature ionic liquid

AbstractThe molar heat capacities of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) were measured by an adiabatic calorimeter in temperature range from 80 to 390 K. The dependence of the molar heat capacity on temperature is given as a function of the reduced temperature X by polynomial equations, CP,m (J K–1 mol–1)= 195.55+47.230 X–3.1533 X2+4.0733 X3+3.9126 X4 [X=(T–125.5)/45.5] for the solid phase (80~171 K), and CP,m (J K–1 mol–1)= 378.62+43.929 X+16.456 X2–4.6684 X3–5.5876 X4 [X=(T–285.5)/104.5] for the liquid phase (181~390 K), respectively. According to the polynomial equations and thermodynamic relationship, the values of thermodynamic function of the BMIBF4 relative to 298.15 K were calculated in temperature range from 80 to 390 K with an interval of 5 K. The glass translation of BMIBF4 was observed at 176.24 K. Using oxygen-bomb combustion calorimeter, the molar enthalpy of combustion of BMIBF4 was determined to be ΔcHmo= – 5335±17 kJ mol–1. The standard molar enthalpy of formation of BMIBF4 was evaluated to be ΔfHmo= –1221.8±4.0 kJ mol–1 at T=298.150±0.001 K.

Graphene oxide and lithium amidoborane: a new way to bridge chemical and physical approaches for hydrogen storage

The incorporation of lithium amidoborane (LiAB) into graphene oxide (GO) and the dehydrogenation process of the GO–LiAB complex have been investigated for combining the chemical and physical hydrogen storage approaches. The obtained adsorption energy and minimum energy pathway (MEP) demonstrate that both of the two dominant groups of –O– and OH– contribute to the facile combination of GO and LiAB (GO3–LiAB). The GO3–LiAB complex has a better dehydrogenation performance than the pristine LiAB, which also indicates the feasibility of doping Li atoms on the GO surface. Atomic charge and bond length analyses match well with the MEP prediction. By dehydrogenation of the GO3–LiAB complex, we also achieve uniform metal doping on the GO surface for physisorption of H2. The GO–Li(n) products can store up to 5 wt% H2 and the GO–(Li3N3B3)(n) can still store 5 wt% H2. The dehydrogenation product of the GO3–LiAB complex has bridged the chemical and physical hydrogen storage approaches to move towards on-board hydrogen storage applications, which expands the scope for designing more efficient hydrogen storage materials.

Molecular cloning and expression of a Relish gene in Chinese mitten crab Eriocheir sinensis

NF‐κB is a B‐cell specific transcription factor that plays crucial roles in inflammation, immunity, apoptosis, development and differentiation. In the present study, a novel NF‐κB‐like transcription factor Relish was cloned from Chinese mitten crab Eriocheir sinensis (designated as EsRelish) by rapid amplification of cDNA ends (RACE) technique based on expressed sequence tag (EST). The full‐length cDNA of EsRelish was of 5034 bp, consisting of a 5′ untranslated region (UTR) of 57 bp, a 3′ UTR of 1335 bp with two mRNA instability motifs (ATTTA), a polyadenylation signal sequence (AATAAA) and a poly (A) tail, and an open reading frame (ORF) of 3645 bp encoding a polypeptide of 1214 amino acids with a calculated molecular mass of 134.8 kDa and a theoretical isoelectric point of 5.26. There were a typical Rel homology domain (RHD), two nuclear localization signal (NLS) sequences (KR), an inhibitor κB (IκB)‐like domain with six ankyrin repeats, a PEST region and a death domain in the deduced amino acid sequence of EsRelish. Conserved domain, higher similarity with other Rel/NF‐κBs and phylogenetic analysis suggested that EsRelish was a member of the NF‐κB family. Quantitative real‐time RT‐PCR was employed to detect the mRNA transcripts of EsRelish in different tissues and its temporal expression in hemocytes of E. sinensis challenged with Pichia methanolica and Listonella anguillarum. The EsRelish mRNA was found to be constitutively expressed in a wide range of tissues. It could be mainly detected in the hemocytes, gonad and hepatopancreas, and less degree in the gill, muscle and heart. The expression level of EsRelish mRNA in hemocytes was up‐regulated from at 3, 6, 9 and 12 h after P. methanolica challenge. In L. anguillarum challenge, it was up‐regulated at 9, 12 and 24 h. The results collectively indicated that EsRelish was potentially involved in the immune response against fungus and bacteria.

Hydrogen storage behavior in C15 Laves phase compound TiCr2 by first principles

Hydrogen storage in TiCr2 alloy of AB(2) type with C15 Laves phase structure has been studied using density functional theory and plane-wave pseudopotential technique. The H atom interacts stronger ...

Hydrogen storage and selective carbon dioxide capture in a new chromium(III)-based infinite coordination polymer

A new chromium(III)-based infinite coordination polymer (ICP) was synthesized under solvothermal conditions. The morphology, particle size and the textural porosity of the resulting solids could be monitored and controlled by adjusting the volume ratio of the solvent mixture (1,4-dioxane/N,N′-dimethylformamide). Two differently textured samples were further compared using powder X-ray diffraction, scanning electron microscopy, FT-IR spectroscopy, solid-state UV-Vis spectroscopy and thermogravimetric analysis. Their sorption capacities for H2, CO2 and CH4 were measured by using volumetric gas adsorption, while the isosteric heats of adsorption for the same gasses were calculated based on gas sorption data at different temperatures. Both samples showed a remarkable selectivity for CO2 over CH4 at 273 K. H2 and CO2 sorption capacities, (respectively 16.9 mg g−1 at 77 K and 817 mm Hg and 168 mg g−1 at 273 K and 760 mm Hg) of the sample composed of the nanosized particles, are comparable or even superior to values reported for most MOFs and ZIFs under similar conditions.

Ultrasonic attenuation in Zr41Ti14Cu12.5Ni10−xBe22.5Cx(x=0,1) bulk metallic glasses under high pressure

The pressure dependence of ultrasonic attenuation in Zr41Ti14Cu12.5Ni10−xBe22.5Cx (x=0,1) bulk metallic glasses has been studied up to 0.5 GPa by using a pulse echo overlap method. The effect of carbon addition on the attenuation is also investigated. Some unique characteristics of the ultrasonic attenuation are found and compared with those of other glasses. The origin of the anomalous attenuation behavior is discussed.