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The KCaF3 perovskite catalyst was successfully synthesized by reacting limestone (natural-CaCO3) with potassium fluoride (KF). The synthesis of the KCaF3 catalyst was conducted with several variations in the mole ratio of CaCO3 to KF (1:1, 1:2, and 1:3). The research results showed that the addition of KF can affect the characteristics of the catalyst. The optimal catalyst is the KCaF3 catalyst with a mole ratio variation of 1:3. X-ray diffractometer analysis revealed that the highest KCaF3 phase composition reached 74.05%, while thermogravimetric analysis indicated a CaCO3 concentration of 34.50%. Surface Area Analyzer analysis shows that KCaF3 has the largest surface area, which is 187.1 m²/g. This catalyst efficiently facilitated the transesterification of palm oil, yielding 93.4% biodiesel. [ABSTRACT FROM AUTHOR]

The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.

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 nickelmodified 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). [ABSTRACT FROM AUTHOR]

The synthesis of CoMo/Mordenite (CoMo/MOR) catalysts was conducted using a co-impregnation method at a various Co/Mo ratios. The produced catalysts were then characterized by X-ray diffraction, total acidity analysis, and scanning electron microscopy. The activity of the catalyst in a hydrotreatment reaction was evaluated by applying the catalyst as a reduced-catalyst to the hydrocracking (HC) reaction of anisole molecules. Analysis of the diffraction data using the Le Bail refinement technique showed that the metal phase was successfully impregnated into the MOR. In addition, increasing the metal content resulted in an increase in the acidity of the catalysts and changed the morphology of the catalysts from homogeneous to heterogeneous with larger particle size. According to the data of GCMS, it is known that the catalysts successfully removed methyl group of anisole molecules. Hydrotreatment reaction with the prepared-catalyst produced 4.77% of phenols. It is 122 % higher than the reaction with MOR catalyst.

The dynamics and structure of Cs+ solvation in an aqueous ammonia solution have been investigated using the Quantum Mechanical Charge Field Molecular Dynamics (QMCF‐MD) simulation method. The system contained 18.6% ammonia in aqueous solution at 298.15 K. The QM region was set to a radius of 7.0 Å to include the first and second solvation shells. The Hartree‐Fock (HF) level was applied to calculate the ion‐ligand and ligand–ligand interactions in the QM region using the LANL2DZ‐ECP basis set for the ion and DZP‐Dunning for the ligands. The radial distribution revealed only one solvation shell, indicating a labile solvation structure. The various coordination number of ligands suggests an instant exchange between them. The mean residence times of 1.29 and 0.9 ps were less than in the pure water and liquid ammonia system, indicating higher mobility ligands of the aqueous ammonia system. The preferential factor 0.55 supports the hypothesis that the Cs+ ion prefers to be dissolved in water. As the ligands moves further away from the ion, the observed number of hydrogen bonds increases, revealing the "structure‐breaking" property of the Cs+ ion. The minimum angle ligand‐ion‐ligand tends to be higher near the ion, confirming this phenomenon. [ABSTRACT FROM AUTHOR]

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This research aims to study the Al-Y dopant to Lithium Lanthanum Zirconate (LLZO) to the characteristics and electrical properties of the LLZO as solid electrolyte. The synthesis was conducted through solid state reaction with Al2O3 and Y2O3 as dopant precursors. X-ray diffraction analysis along with Le Bail refinement was done to understand their structure, and phase content inside. The result found that Al and Y doping increased the cubic phase from 49.58% to 84.91%. The Al-Y doped-LLZO (LLZAYO) powder was then treated by a various cold isostatic pressing, CIP of 0, 20, 30, and 40 MPa to understand the effect of cold isostatic pressure to the ionic conductivity and solid electrolyte performance of the material even without heat sintering treatment. The result found that the green pellet of LLZAYO) which was isostatically pressed by 40 MPa at room temperature provides (9.06 -0.26) x10-6 Scm-1, about 8 times higher than the LLZO without doping, i.e., (1.25 -0.01) x 10-6 Scm-1. All solid-state battery with the prepare LLZAYO CIP 40 as solid electrolyte shows reversible reaction of Li/Li+ redox accompanied with Al/Al3+ redox. The Al/Al3+ reaction seems to decrease the electronic resistance between LCO-LLZAYO CIP40-Li which causes the full cell performance to decrease. The initial specific charging capacity is 82 mAh/g, and the initial discharge was 83 mAh/g, confirming 101 % of Coulombic efficiency. The discharge capacity drops to 46 mAh/g at second cycle, leading to a decrease in Coulombic efficiency to 56 %. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this research, a low mole ratio formula Li to Zr of Li0.5xLa0.5xZr1−xO12−δ(LLZO*) with various x = 0.1, 0.3, and 0.6 was synthesized. The research aims to understand the crystal structure and the electrochemical properties of the new formula of Li0.5xLa0.5xZr1−xO12−δ, in which the Li to Zr mole ratio is smaller than the common cubic garnet of Li7La3Zr2O12 (LLZO). A different sintering treatment was also applied to understand whether the material properties are only a matter of chemical formula or are also affected by the sintering method. The first sintering method was firing at 1230 °C for 6 h under air to produce LLZO*(A), and the second method was firing at 900 °C for 6 h under Ar flows to produce LLZO*(B). The XRD analysis found that the LLZO*(A) was crystallized mainly to tetragonal structure, and cubic pyrochlore secondary phase, with a small amount of cubic structure. Meanwhile, the LLZO*(B) was crystallized mainly into cubic and tetragonal structure. The impedance analysis found that LLZO*(B) shows a higher ionic conductivity than LLZO*(A), i.e., 7.573 × 10−5 S.cm−1. A full-cell impedance measurement of LiFePO4-LLZO*(B)-mcmb shows that LLZO*(B) x = 0.1 has the lowest Li+ migration resistance of 223.8 Ω confirming the promising material for solid electrolyte. [ABSTRACT FROM AUTHOR]

The electrical properties of graphene doped with graphite and N-pyridine and their interaction with K+ ions have been studied using the density-functional based tight-binding (DFTB) method. Pure graphene and graphene with a single vacancy are used as comparisons. A 4 × 4 × 1 unit cell was used as the base, while an enlarged supercell consisting of primitive unit cells repeated to 40 × 40 × 1 was used for sampling. The structure and the Fermi Level of the optimized graphene agreed with the experimental data. The presence of N as a dopant in a graphitic configuration shifted the Fermi level to higher levels, while N in a pyridinic configuration shifted it to lower. Both showed an increase in the intensity of electronic activity. The presence of the dopant N resulted in the widening of the bandgap in graphene. The electrical characteristics of the examined graphenes influence the strength of the interaction with K+ ions. The band structure of graphene, N-graphitic graphene, defect-graphene, and N-pyridinic graphene reveals the band opening features that influence adsorption interactions with K+ ions. The ease with which K+ ions interact on the graphene surface is facilitated by a larger bandgap energy. The bandgap energies of vacantcy-containing graphene and N-pyridine-doped graphene are larger, leading to greater K+ ion interactions. In the pyridine arrangement, the presence of N doping degrades graphene symmetry, changes Fermi levels and increases the bandgap. The greater the bandgap, the stronger the interaction of graphene with K+ ions. The interaction between K+ ions and N-pyridine-doped graphene, however, results in an energy that is too high in this approach. [ABSTRACT FROM AUTHOR]

In this research, a low mole ratio formula Li to Zr of Li0.5xLa0.5xZr1−xO12−δ(LLZO*) with various x = 0.1, 0.3, and 0.6 was synthesized. The research aims to understand the crystal structure and the electrochemical properties of the new formula of Li0.5xLa0.5xZr1−xO12−δ, in which the Li to Zr mole ratio is smaller than the common cubic garnet of Li7La3Zr2O12 (LLZO). A different sintering treatment was also applied to understand whether the material properties are only a matter of chemical formula or are also affected by the sintering method. The first sintering method was firing at 1230 °C for 6 h under air to produce LLZO*(A), and the second method was firing at 900 °C for 6 h under Ar flows to produce LLZO*(B). The XRD analysis found that the LLZO*(A) was crystallized mainly to tetragonal structure, and cubic pyrochlore secondary phase, with a small amount of cubic structure. Meanwhile, the LLZO*(B) was crystallized mainly into cubic and tetragonal structure. The impedance analysis found that LLZO*(B) shows a higher ionic conductivity than LLZO*(A), i.e., 7.573 × 10−5 S.cm−1. A full-cell impedance measurement of LiFePO4-LLZO*(B)-mcmb shows that LLZO*(B) x = 0.1 has the lowest Li+ migration resistance of 223.8 Ω confirming the promising material for solid electrolyte. [ABSTRACT FROM AUTHOR]