Search

ABSTRACT. Bio-oil is a renewable energy source with high oxygen levels, and anisole is a chemical widely employed in research to represent it. Catalytic hydrodeoxygenation (HDO) reduces the oxygen content. A catalyst known as nickel-modified HZSM-5 has shown promising results for HDO. Meanwhile, catalyst efficiency depends on the Ni/HZSM-5 ratio. So, this study aims to determine how the Ni/HZSM-5 ratio influences the catalyst's properties, activity, and selectivity in anisole HDO. The Ni/HZSM-5 catalyst was made using the wet impregnation method with various ratios of Ni/HZSM-5. The catalysts were analyzed for their morphology using scanning electron microscopy-energy-dispersive X-ray (SEM-EDX). The diffraction patterns were studied using X-ray diffraction (XRD). Surface area and porosity were determined through gas sorption analysis (GSA). Then, the acidity strength was evaluated via temperature-programmed ammonia desorption (NH3-TPD). The characterization results show Ni was successfully impregnated and distributed evenly in HZSM-5 without changing the primary structure. Adding Ni metal to HZSM-5 increases the surface area of the catalyst but reduces its acid strength. The catalytic performance of the catalysts was then evaluated in a flow reactor at 400 °C, using 15 mL/min H2 gas. The liquid products of the reaction were analyzed using gas chromatography-mass spectroscopy (GC-MS). The results of the catalytic performance show that Ni4.5/HZSM-5 has the highest catalytic activity in anisole conversion. At the same time, Ni6.4/HZSM-5 shows the highest selectivity towards benzene-toluene-xylene (BTX). Keywords: Hydrodeoxygenation, nickel, anisole, heterogeneous catalyst, acidity.

Defects in graphene alter its structure, electrical characteristics, and interaction with K+ ions. The related characteristics of divacancy defect graphene and N, S codoped divacancy graphene were effectively explored using the DFTB technique. Divacancy is essential for the band gap opening. The dopants considerably enhance the density of state (DOS) intensity and alter the graphene-character bands. The depletion of density caused by the dopant is seen on the charge density isosurface. Because the charge of the K+ ion is balanced by the dopant, the ion prefers to be adsorbed on divacancy graphene with dopants.

The preparation of biosorbent from kapok fruit peel (KBK) for lead (Pb(II)) removal was conducted mechanically by expanding the surface of the biosorbent and activating KBK with the addition of 1 M HCl for 20 minutes. The effect of activation on increasing the number of active groups and the number of pores in the biosorbent was proven by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The FTIR data showed a shift and an increase in wavenumber intensities of active adsorbent groups such as -OH and -C=O. The SEM data revealed that the morphology of the adsorbent increased in the number of pores that appeared rough and irregular. The Pb(II) adsorption treatment used a batch method at pH 2–5, contact time of 0–120 minutes, and adsorbate concentration of 10–50 ppm. The adsorption of Pb(II) ions reached optimum conditions at pH 4 and a contact time of 60 minutes, with an adsorption capacity of 6.9522 mg/g and an adsorption rate of 98.71%. Adsorption data showed that Pb(II) ions uptake to KBK biosorbent followed the Langmuir isotherm model equation and pseudo-second-order kinetic model. The adsorption capacity of activated KBK is greater than that of non-activated KBK.

A study on the effect of S doping and K+ adsorption to the electronic properties of graphene has been conducted by DFTB (Density Functional Tight Binding) calculation. The supercell of 40 x 40 x 1 configured from the 4x4x1 unit cell of graphene was optimized. The calculation shows that the Fermi level of graphene shifted from -4.67 eV into -3.57 eV after S doping. In addition, the S presence caused the formation of gap within the Dirac K of valence band and conduction band. Meanwhile, K+ charge distribution was dominantly occurred within the S-graphene than the graphene.

The amount of loaded Co-Mo metal on the Y-Zeolite Ultra Stable (USY) was increased by the addition of activated carbon in the pre-impregnation process. USY modification was done by adding activated carbon to USY as much as 10 wt%. The process of adding activated carbon is carried out by three methods, i.e., grinding with sucrose binder (ACU1), without sucrose (ACU2), and conducting by ball milling (ACU3). Wet impregnation method was employed to disperse the Co and Mo, sequentially. Composites were characterized using Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and surface area analyzer (SAA). Metal dispersions were observed by X-ray fluorescence (XRF). The FTIR suggests an interaction between USY and activated car-bon, while the XRD result indicated the none structural transformation of USY zeolite. The SAA analysis showed an increased total pore radius with the activated carbon addition. The XRF confirmed the increasing of total metals dispersion of 6.25% (ACU1); 5.48%(ACU2); 5.18% (ACU3); compare to USY origin with 3.28% metals loaded.

Bioflavonoids from grape seeds feature powerful antioxidant and immunostimulant activities, but they present problems related to solubility and bioavailability. Nanocrystal (NC) incorporated into a mesoporous carrier is a promising strategy to address these issues. However, the preparation of this formulation involves the selection of factors affecting its critical quality attributes. Hence, this study aimed to develop an NC formulation incorporating resveratrol into a soluble mesoporous carrier based on rational screening design using a systematic and continuous development process, the quality-by-design paradigm. A mesoporous soluble carrier was prepared by spray-drying mannitol and ammonium carbonate. The NC was obtained by introducing the evaporated solvent containing a drug/polymer/surfactant and mesoporous carrier to the medium. A 26−2 fractional factorial design (FFD) approach was carried out in the screening process to understand the main effect factors. The type and concentration of polymer and surfactant, resveratrol loading, and solvent were determined on the NC characteristics. The results indicated that drug loading, particle size, and solubility were mainly affected by RSV loading, PEG concentration, and Kolliphor EL concentration. The polymer contributed dominantly to reducing the particle size and enhancing solubility in this screening design. The presence of surfactants in this system made it possible to prolong the supersaturation process. According to the 26−2 FFD, the factors selected to be further developed using a statistical technique according to the quality-by design-approach, Box Behnken Design, were Kolliphor EL, PEG400, and RSV loading.

Ab initio of Quantum Mechanics Charge Field Molecular Dynamic (QMCF-MD) of K(I) ion in liquid ammonia has been studied. A Hartree-Fock level of theory was coupled with LANL2DZ ECP basis set for K(I) ion and DZP (Dunning) for ammonia. Two regions as first and second solvation shell were observed. In the first solvation shell at distance 3.7 (Å), K(I) ion was coordinated by four to eight ammonia molecules dominated by K(NH3)6+ species. Second shell of solvation was ranging between 3.7 Å to 7.3 Å. Within simulation time of 20 ps, the frequent exchange processes of ligands indicating for a very labile solvation structure. Four mechanism types of ligand exchange between first and second solvation shell were observed. Mean residence time of ligand is less than 2 ps confirming weak in ion-ligand interaction. Evaluation of K(NH3)6+ using natural bond orbital analysis shows that the Wiberg bond Index is less than 0.05 indicating weak electrostatic interaction of K-N.