Nanocatalysts Derived from Copper Phyllosilicate for Selective Hydrogenation of Quinoline

1,2,3,4-Tetrahydroquinoline (py-THQ) is a vital intermediate that is used in the production of medicines, agricultural chemicals, and other fine chemicals and is synthesized through the selective hydrogenation of quinoline. In this work, copper phyllosilicate catalysts were prepared by four different synthesis methods: deposition precipitation, ammonia evaporation, a urea-assisted gel method, and hydrothermal treatment. It was found that the different synthesis strategies led to different actual loadings of copper in the precursors. The optimal catalyst showed a py-THQ selectivity of 99.9% at a full conversion of quinoline in ethanol at 100 °C and 3.0 MPa H2 for 2 h. The remarkable enhancement of the performance may be attributed to the small particle size, the coexistence of Cu0 and Cu+, and the strong interaction of copper phyllosilicate by the deposition precipitation preparation method. The characterization results showed that Cu0 and Cu+ were generated during the restoration process and were derived from CuO and layered copper phyllosilicates, respectively. Additionally, the ratio of Cu+/(Cu+ + Cu0) changed with the reduction temperature. The strategy of the catalyst design and synthesis developed in this work has potential applications in other nitrogen heterocyclic hydrogenation reactions

Enhanced Rate Performance of Al-Doped Li-Rich Layered Cathode Material via Nucleation and Post-solvothermal Method

Al-doped layered cathode materials Li_{1.5–<i>x</i>}Al_<i>x</i>Mn_0.675Ni_0.1675Co_0.1675O₂ have been successfully synthesized via a rapid nucleation and post-solvothermal method. The surface morphology and crystal structures of Al-doped Li-rich materials are investigated via scanning electron microscopy, X-ray diffraction, Raman spectra, and X-ray photoelectron spectroscopy. After optimization, the Li_1.45Al_0.05Mn_0.675Ni_0.1675Co_0.1675O₂ (Al = 0.05) sample showed excellent electrochemical performance, and the discharge capacities are 323.7 and 120 mAh g^–1 at a rate of 0.1 and 20 C, respectively. These improvements, based on electrochemical performance evaluation and density functional theory calculations, might be ascribed to the increased electron conductivity of layered Li-rich material via Al³⁺ ions doped into a crystal structure

Solid Polymer Electrolyte Based on Polymerized Ionic Liquid for High Performance All-Solid-State Lithium-Ion Batteries

Polymerized ionic liquids (PILs) have several advantages over ionic liquids, such as easy handling, good electrochemical performance, and chemical compatibility. In this research, a solid-state electrolyte composite membrane was successfully fabricated by using an imidazolium-based polymerized ionic liquid as polymer matrix, a kind of porous fiber cloth as rigid frame, and lithium bis­(trifluoro­methane­sulfonyl)­imide (LiTFSI) as lithium salt. The ionic conductivity of the composite electrolyte with 2.0 mol/kg LiTFSI is 7.78 × 10–5 S cm–1 at 30 °C and reaches 5.92 × 10–4 S cm–1 at 60 °C, which is considered a satisfactory value for potential application in lithium-ion batteries. The specific discharge capacity of the LiFe­PO4/Li cell with as-prepared composite electrolyte is 138.4 mAh g–1, and 90% of the discharge capacity is retained after 250 cycles at 60 °C. In order to further improve the conductivity, Li1.3­Al0.3­Ti1.7­(PO4)3 (LATP) ceramic electrolyte particles are dispersed in a PIL polymer matrix to prepare the PIL-LiTFSI-LATP composite electrolyte. LiFe­PO4/Li cells using PIL-LiTFSI-LATP (10 wt % LATP) as a solid-state electrolyte exhibit excellent rate performance and high capacity retention (close to 97% after 250 cycles at 60 °C). This work may provide a unique way to prepare a new series of electrolytes for high-performance solid-state lithium batteries