Nonsacrificial Nitrile Additive for Armoring High-Voltage LiNi0.83 Co0.07 Mn0.1 O2 Cathode with Reliable Electrode-Electrolyte Interface toward Durable Battery.

High-capacity Ni-rich layered oxides are considered as promising cathodes for lithium-ion batteries. However, the practical applications of LiNi0.83 Co0.07 Mn0.1 O2  (NCM83) cathode are challenged by continuous transition metal (TM) dissolution, microcracks and mixed arrangement of nickel and lithium sites, which are usually induced by deleterious cathode-electrolyte reactions. Herein, it is reported that those side reactions are limited by a reliable cathode electrolyte interface (CEI) layer formed by implanting a nonsacrificial nitrile additive. In this modified electrolyte, 1,3,6-Hexanetricarbonitrile (HTCN) plays a nonsacrificial role in modifying the composition, thickness, and formation mechanism of the CEI layers toward improved cycling stability. It is revealed that HTCN and 1,2-Bis(2-cyanoethoxy)ethane (DENE) are inclined to coordinate with the TM. HTCN can stably anchor on the NCM83 surface as a reliable CEI framework, in contrast, the prior decomposition of DENE additives will damage the CEI layer. As a result, the NCM83/graphite full cells with the LiPF6-EC/DEC-HTCN (BE-HTCN) electrolyte deliver a high capacity retention of 81.42% at 1 C after 300 cycles at a cutoff voltage of 4.5 V, whereas BE and BE-DENE electrolytes only deliver 64.01% and 60.05%. This nonsacrificial nitrile additive manipulation provides valuable guidance for developing aggressive high-capacity Ni-rich cathodes.

Carbon dioxide conversion to fuel over alumina-supported ruthenium catalysts.

In this study, ruthenium-based catalysts were prepared for CO2 hydrogenation. Incipient-wetness-impregnation of the alumina-support with ruthenium (III) nitrosyl nitrate solution to achieve 0.5 wt% Ru loading on supports was used to prepare these catalysts. Potassium (0-3 % wt%) was used to further promote the catalysts. TPR, CO2-TPD, XRD, TEM, XPS, SEM, and EDS analyses were used to characterize catalyst properties. The hydrogenation of CO2 catalytic tests were conducted and the effect of operating conditions (temperature, pressure, and space velocity) were investigated. These studies were conducted in a tubular fixed-bed reactor. The CO2 conversion over these catalysts was found to be low and the dominating product observed was CH4 with a small amount of C2+ forming when K was added to the catalyst. The optimum potassium loading for improved C2+ product yield over Ru/Al2O3 was 1%K for CO2 hydrogenation.

Optimization and evaluation of the distribution of Fischer-Tropsch products over a cobalt-based catalyst utilising design expert software.

Modelling biomass to liquid via the Fischer-Tropsch synthesis (FTS) system allows researchers to investigate the most efficient parameters while running the system under optimal conditions. As part of the design of experiments (DOE) procedure, a special data simulation method based on response surface methodology (RSM) is utilized to thoroughly analyse the impact of operating circumstances. The objective of this study was to examine the factors that affect the production of C1, C2-C4, and C5+ in FTS process, and then optimize the critical factors utilising factorial design and response surface techniques. The parameters evaluated were reaction temperature, reaction pressure and the crystallite size of cobalt. The effects of these factors and their potential for synergy were explored simultaneously using multivariate DOE, with the yield of different hydrocarbon composition selectivity's as the measured responses. In the concept generation phase, optimization was based on the literature consulted, which proved to be an effective method for determining the optimization parameters. The detailed conceptual design included the generation of models using statistical methods and response surface models. Finally, the optimized design was validated using catalysts and parameters obtained during the optimization process, and this were compared to the output recorded in the theoretical modelling. The optimized parameters resulted in performance consistency, with the theoretical model for each group of hydrocarbons being validated by actual experiments. The established models were seen to characterize hydrocarbon distributions accurately and repeatedly over a wide range of reaction conditions (200-270 °C, 5-20 Bar, and 3-26 nm) using a cobalt-based catalyst. According to the detailed quantitative models developed, for higher C5+ production, 220 °C, 10 barg and 11 nm (cobalt crystallite) benchmark parameters were set to produce 19.3 % C1, 11.4 % C2-C4 and 69 % C5+ selectivity's. Comparative analysis showed a 1.9 %, 3.9 % and 0.3 % percentage difference between the theoretical output and the actual output of C1, C2-C4 and C5+, respectively.

Modulating the Band Structure of Metal Coordinated Salen COFs and an In Situ Constructed Charge Transfer Heterostructure for Electrocatalysis Hydrogen Evolution.

A series of crystalline, stable Metal (Metal = Zn, Cu, Ni, Co, Fe, and Mn)-Salen covalent organic framework (COF)EDA complex are prepared to continuously tune the band structure of Metal-Salen COFEDA , with the purpose of optimizing the free energy intermediate species during the hydrogen evolution reaction (HER) process. The conductive macromolecular poly(3,4-ethylenedioxythiophene) (PEDOT) is subsequently integrated into the one-dimensional (1D) channel arrays of Metal-Salen COFEDA to form heterostructure PEDOT@Metal-Salen COFEDA via the in situ solid-state polymerization method. Among the Metal-Salen COFEDA and PEDOT@Metal-Salen COFEDA complexes, the optimized PEDOT@Mn-Salen COFEDA displays prominent electrochemical activity with an overpotential of 150 mV and a Tafel slope of 43 mV dec-1 . The experimental results and density of states data show that the continuous energy band structure modulation in Metal-Salen COFEDA has the ability to make the metal d-orbital interact better with the s-orbital of H, which is conducive to electron transport in the HER process. Moreover, the calculated charge density difference indicates that the heterostructures composed of PEDOT and Metal-Salen COFEDA induce an intramolecular charge transfer and construct highly active interfacial sites.