Zeolite imidazolate frameworks (ZIFs) have been applied to gas adsorption, but there remain no reports detailing the adsorption–desorption process for lanthanum metal ion (LMI). This work first testifies that ZIF-8 has a better adsorption property than ZIF-90 for remediation of LMI from water. Adsorption results demonstrate that ZIF-8 removes 100.0% of the metals ions, whose concentrations are below 20 mg L–1, and the saturated adsorption capacity is 385 mg g–1. Characterization by P-XRD, ICP, and FT-IR indicates that the main structure of ZIF-8 remained unchanged to a large extent during the adsorption process. Density functional theory (DFT) calculations illustrated that the adsorption process is spontaneous, and the adsorption site is in the center of two imidazole rings. La-ZIF-8 was subjected to two polar desorbents, acetonitrile and methyl alcohol, possessing a desorption ratio of 94.4% and 61.0%, respectively. Recycling the adsorption/desorption process using acetonitrile resulted in significant crystal structure collapse after three recycles reducing the adsorption capacity to 150 mg g–1. However, acetonitrile still maintains a desorption ratio of over 90.0%. Our work shows that ZIF-8 can be used as an efficient adsorbent in the removal of aquatic LMI, especially at trace concentration levels.

The structures and thermal properties of Ag–Pt–Ni ternary nanoclusters varying with different compositions and sizes are studied by Monte Carlo and molecular dynamics simulations. It can be found that silver atoms tend to occupy the surface and platinum atoms favor the subsurface occupation, whereas the inner is occupied by nickel atoms due to the different surface energies and lattice parameters. In addition, there is a non-monotonous relationship between the melting points and compositions of Ag–Pt–Ni ternary nanoclusters according to molecular dynamics simulations. In addition, a linear decrease in melting point with \(N^{ - 1/3}\) is found for both monometallic and trimetallic clusters. This behavior is consistent with Pawlow’s law.

Olefins and paraffins are important basic chemical raw materials with so similar molecular structure and volatility that their separation is a difficult and energy-consuming process. Liquid—liquid equilibrium (LLE) data were determined for ternary systems of: 1-hexene + hexane + solvent at 25°C, 30°C, and 35°C, and N-formylmorpholine (NFM), N-methyl-2-pyrrolidone (NMP), γ-butyrolactone (GBL), and 1-methylimidazole (1-MEI) as the solvents studied. Liquid—liquid equilibrium data for each system were correlated to the NRTL (Non-Random Two Liquid) equation and the interaction parameters presented. The calculated results agree well with the experimental data.

•Cu@CuPt core@shell nanowires were synthesized in organic solvent medium.•PtCu nanowires exhibit superior catalytic activity toward the oxygen reduction reaction.•PtCu nanowires show much better durability than the commercial Pt/C catalyst.•Theoretical studies are used to understand the mechanism of enhanced ORR activity.Pt-based core–shell electrocatalysts with one-dimensional (1D) nanostructure show a great opportunity to improve the catalytic activity and durability of pure Pt catalyst for oxygen reduction reaction (ORR). Here, we synthesize Cu@CuPt core@shell nanowires (NWs) with 1D nanostructure by using Cu NWs as templates in organic solvent medium. The ORR mass activity and specific activity of PtCu NWs are 0.216 A mgpt−1 and 0.404 mA cm−2 at 0.9 V, respectively, which are 3.1 and 3.7 times larger than that of the commercial Pt/C catalyst (0.07 A mgpt−1 and 0.110 mA cm−2, respectively). Theoretical studies suggest that the electronic effect of the Cu substrate on the Pt monolayer could be the main reason for the higher activity of PtCu NWs than that of the commercial Pt/C catalyst. In addition, the PtCu NWs show much better durability than the commercial Pt/C catalyst after stability test. It is expected that the as-synthesized PtCu NWs in organic solvent medium could be excellent candidates as high performance catalysts for ORR.

In this work, CO adsorption and oxidation on free and defective graphene-supported AumPdn (m + n = 13) clusters with either icosahedral (ICO) or truncated octahedral (TO) structures are investigated using density functional theory calculations. It is found that CO adsorbs more strongly than molecular O2 on the surface of these clusters, which is attributed to the strong hybridization between metal-d and C-p orbitals. In addition, the structural transformation from ICO to TO is observed for the Au-rich clusters upon CO and O2 adsorption because the stability of the ICO cluster is lower than that of the TO one. It is also found that the free Au12Pd1 cluster with TO structure exhibits the lowest energy barrier for CO oxidation among the free clusters (0.17 eV). When the Au12Pd1 cluster is supported on the single vacancy defective graphene, an increase in stability, a decrease in the adsorption strength of CO and O2, and a slight increase in the energy barrier (0.41 eV) for CO oxidation compared to the corresponding free cluster are observed. Our results are expected to be useful for future applications of graphene-supported bimetallic nanocatalysts.

A mixture of organic solvent and ionic liquid (IL) was proposed as entrainer for the ethanol/water separation by extractive distillation. The vapor–liquid equilibrium (VLE) experimental results showed that the relative volatility of ethanol to water is significantly enhanced using the ethylene glycol (EG) and [EMIM]+[Ac]− mixed entrainers when compared to that of the benchmark solvent EG. The nonrandom-two-liquid model parameters were correlated using the measured ternary and quaternary experimental VLE data. On this basis, process simulation was carried out to evaluate the improvement of the proposed mixed entrainers. It was found that for the ethanol/water separation using the mixed entrainers, the overall heat duties on reboilers in the processes without and with heat integration (HI) decrease 11.53% and 10.34%, respectively, when compared to the conventional benchmark solvent EG. Moreover, the presented process intensification method is easily achieved in practice by substituting the proposed mixed entrainers for the conventional solvent without changing the whole flowsheet.

Seasonal energy storage based on phase-change materials (PCMs), long-chain alkylimidazolium bromide ionic liquids [C16MIM]Br and [C16MMIM]Br, are investigated in this paper. The structures of ionic liquids are measured by infrared (IR) spectra. Thermodynamic properties of ionic liquids, such as melting/freezing temperature and endothermic/exothermic heat, are measured by differential scanning calorimetry (DSC). The active use of supercooling of ionic liquids is proposed, which means that the thermal energy is stored in a supercooled liquid state and released by nucleating agents when needed. Copper powder and graphite powder, used as nucleating agents, are added with different mass fractions (0−25 wt %), and their effects on the thermodynamic properties of two ionic liquids are investigated. The results show that the nucleating agents have little effect on the thermodynamic properties of ionic liquids. The degree of supercooling of [C16MIM]Br is maintained at about 20 K when copper powder or graphite powder is added. The proper melting point and stable supercooling state of [C16MIM]Br indicates that it is more suitable for seasonal energy storage.

The focus of this work was to concentrate aniline at low concentration from water samples using liquid−liquid extraction with salts. The salts included inorganic solid salts and ionic liquids and were added to the system of water + aniline + MTBE (methyl tert-butyl ether) to intensify the conventional liquid−liquid extraction process. The influence of such factors as extraction time, initial aqueous aniline concentration, phase volume ratio, and extraction temperature on the extraction process was investigated to determine the optimum extraction conditions. It was found that the salting effect of K2CO3 on aniline and water is the highest among all of the salts investigated, whereas the imidazolium-based ionic liquids do not bring about a good extraction efficiency as expected. The complex formation and interaction force of the systems containing salts were determined using FTIR (Fourier transform infrared) spectrometry and density functional theory (DFT). This work also tries to explain the separation mechanism by means of the Hofmeister series and quantum chemistry.