Search

The dissolution of intermediate lithium polysulfide within the electrolyte presents a significant challenge in lithium-sulfur batteries (Li–S). While an increasing number of recent studies on Li–S are focused on using activated carbon (AC) cathodes due to their strong affinity to lithium polysulfide, there still has been limited investigation into the quantitative adsorption of lithium polysulfide across various ratios of urea doping with AC. This study thus aims to quantitatively study the polysulfide adsorption capabilities of biomass-based carbon material activated by KOH and doped with urea. The correlation between N-doped surface morphology and lithium polysulfide in the AC was thoroughly investigated. The results indicate that increasing the urea ratio improves AC's porosity and enhances the lithium polysulfide adsorption. AC prepared with the highest biomass: urea ratio of 1:3 in this study exhibits the most remarkable adsorption uptake capacity of 12.94 mmol/g. This excellent adsorption performance is attributed to the synergistic effect of well-developed porosity (BET surface area of 1902.99 cm2/g and a pore volume of 0.92 cm3/g) and high nitrogen functionalization on the carbon surface, contributing to the formation of physical and chemical bonds between polarized lithium polysulfide and the carbon matrix that enhances the adsorption process. [ABSTRACT FROM AUTHOR]

A new biocomposite cross-linked glutaraldehyde-chitosan/MgO/Fe3O4 (CTS-GL/MgO/Fe3O4) adsorbent with magneto-responsiveness was prepared and applied for the removal of reactive blue 19 (RB-19), a synthetic textile dye. The prepared CTS-GL/MgO/Fe3O4 was structurally characterized using spectroscopic (XRD, FTIR, SEM–EDX), and its physicochemical properties were evaluated using potentiometry and pHpzc analyses. The influence of various adsorption parameters (A: CTS-GL/MgO/Fe3O4 dosage; B: initial solution pH; C: process temperature; and D: contact time) on the removal efficiency of RB-19 was statistically optimized using Box-Behnken design (BBD). The analysis of variance (ANOVA) indicates the presence of five significant statistical interactions between the adsorption parameters, as follows: AB, AC, AD, BC, and BD. The equilibrium dye uptake by the Freundlich isotherm model indicates heterogeneous adsorption, while the kinetics of adsorption was well-described by the pseudo-second-order model. The maximum adsorption capacity of CTS-GL/MgO/Fe3O4 towards RB-19 was 193.2 mg/g at 45 °C. This work highlights the development of a recoverable magnetic biocomposite adsorbent with favourable adsorption capacity towards a model textile dye with good separation ability by using an external magnetic field. Moreover, separation of the magnetic adsorbents from the treated solution is easy and convenient apply to continuous flow systems, which is highly preferred for industrial applications. [ABSTRACT FROM AUTHOR]

Bio-oil derived from fast pyrolysis of oil palm empty fruit bunch (EFB) was catalytically reformed inside a stainless steel multichannel tubular reactor using steam and air as reforming agents. The catalyst used, denoted as Fe/AC, was an iron catalyst loaded on the coconut shell-derived activated carbon (AC) prepared by a new approach of impregnating iron from an aqueous solution onto the AC in a stepwise manner. Results indicate that a stepwise impregnation was able to minimise the agglomeration of iron particles on AC surface, allowing high loading of iron onto the AC without severely affecting Fe dispersion and catalyst pore properties. The highly reducible, highly efficient catalyst produced in this study was able to lower the concentration of tar in producer gas to lower than 100 mg/Nm3. The best composition of the burnable product gas was obtained with iron loading of 15 wt%, reaction temperature of 800 °C, steam-to-carbon molar ratio (S/C) of 1.0 and air equivalence ratio (ER) of 0.1, with gas composition of 33.5% H2, 21.0% CO, 14.0% CH4, 18.8% CO2 and 1% C2 hydrocarbons and a cold gas efficiency of 78.5%. [ABSTRACT FROM AUTHOR]

In this work, partial substitution or doping of SrCo0.8Fe0.2O3-δ (SCF), which leads to the formation of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and La0.6Sr0.4Co0.2Ni0.8O3-δ (LSCNi) were carried out using Pechini sol-gel technique. The perovskite oxides sol was then calcined at 850 °C for 4 h and their crystallinity, morphology and oxygen sorption/desorption behaviour were systematically compared. It was found that the synthesised perovskite oxides exhibit single-phase cubic perovskites. The O2-TPD analysis indicates that LSCNi adsorbed the largest amount of oxygen and SCF only performed better at higher operating temperature. From the fixed bed test, LSCF and LSCNi are found to have high potential to be used as O2 sorbent for high-temperature air separation because they required shorter time to achieve the breakthrough curve.Sol-gel derived perovskite-based sorbents were synthesised for high temperature air separation and the effects of partial substitution/doping on the structure and morphology of MIEC perovskite oxides were discussed. Doping of perovskite-based sorbents were successfully carried out using sol-gel technique.The O2-TPD analysis indicates that LSCNi adsorbed the largest amount of oxygen.Doping of La3+ into A-site and Ni2+ into B-site ion has improved the oxygen sorption properties.LSCF and LSCNi can be used as O2 sorbent as they have shorter breakthrough time. [ABSTRACT FROM AUTHOR]