Khoirina D Nugrahaningtyas - Academia.edu (original) (raw)

Papers by Khoirina D Nugrahaningtyas

Evergreen, Mar 1, 2024

In this study, pectin encapsulated Na-zeolite A particles (P-ZA) was synthesized using the impreg... more In this study, pectin encapsulated Na-zeolite A particles (P-ZA) was synthesized using the impregnation method and it was used as an adsorbent for adsorption of multicomponent lanthanides ions. The Na-zeolite A (zeolite A) was prepared from natural kaolin by the hydrothermal method, while pectin was isolated from white pith of citrus maxima fruits. Scanning electron microscope (SEM) images suggested that P-ZA composite adopts a nest-like shaped surface morphology occupied by zeolite A particles or pectin encapsulated skeleton system of zeolite A particles. The size of P-ZA particles was approximately 125 μm. The highest adsorption capacity of La 3+ , Ce 3+ , Nd 3+ , Sm 3+ , and Dy 3+ on P-ZA composite is 4.81×10-5 M, 4.65×10-5 M, 6.19×10-5 M, 6.04×10-5 M, and 6.03×10-5 M, respectively, at the contact time of 60 mins. The lanthanides ions are adsorbed on the P-ZA surfaces through either ion exchange with Na-zeolite A or coordination with the functional groups of pectin, and are further stabilized by their hydrolysis on the P-ZA surfaces. The results suggest that P-ZA composite has the potential to be utilized as an adsorbent for the initial step of separation and purification of lanthanides after leaching from the metallurgical ores.

Ingeniería e Investigación/Ingeniería e Investigación, Feb 23, 2024

Evergreen, Jun 1, 2022

Vegetable oil is a promising alternative fuel source, but the high content of oxygenate compounds... more Vegetable oil is a promising alternative fuel source, but the high content of oxygenate compounds reduces its performance. Therefore, in this study, a Co-and Mo-based catalyst was synthesized with Ultra Stable Y-zeolite (USY), Mordenite (MOR), or activated Indonesian natural zeolite (ANZ) as supports, to reduce the oxygen content of the vegetable oil model compounds. The type of metal phase is similar in each support, except for the MoO3 phase, which is disappeared in AZN. The addition of metal causes a change in electron density and reduces the specific surface area. Meanwhile, CoMo/USY showed the best performance with a gasoline fraction selectivity of 85.7%.

Jurnal Rekayasa Proses, Mar 24, 2023

OBJECTIVES The first-period transition metal catalyst (M=Fe, Co, Ni, Cu, or Zn) based on Socony M... more OBJECTIVES The first-period transition metal catalyst (M=Fe, Co, Ni, Cu, or Zn) based on Socony Mobil-5 Hydrogen Zeolite (HZSM-5) is a promising catalyst for various reactions. The periodicity of activity and the stability of the catalyst structure in the anisole cracking reaction will be investigated in this study. METHODS The impregnation method was used to synthesize the M / HZSM-5 catalyst at a fixed metal concentration of 0.025 M. A semi-flow reactor was used for the catalytic test. The product was analyzed using a gas chromatography-mass spectrometer (GC-MS). The fresh and used-catalyst characteristics, such as crystallinity and phase composition, were analyzed using X-ray diffraction (XRD). The fresh and used-catalyst characters, such as crystallinity and phase composition, were analyzed using X-ray diffraction (XRD). While, the surface area and porosity were analyzed using a surface area analyzer (SAA). RESULTS The results revealed that the catalyst had a variety of activities, with the optimum value occurring in the anisol cracking reaction using the Zn/HZSM-5 catalyst. The phase composition of each used catalyst changed slightly, especially in the Fe/HZSM-5 and Co/HZSM-5 catalysts, while the surface area and porosity decreased. CONCLUSIONS The catalyst's activity and stability do not follow the periodicity of the constituent elements.

Jurnal Penelitian Saintek, Mar 1, 2015

Penelitian ini bertujuan untuk mengetahui pengaruh katalis Mo-Co/USY terhadap distribusi dan konv... more Penelitian ini bertujuan untuk mengetahui pengaruh katalis Mo-Co/USY terhadap distribusi dan konversi produk serta pengaruh penambahan logam Co terhadap selektivitas produk benzena pada reaksi hidrodeoksigenasi (HDO) anisol. Reaksi HDO anisol dilakukan dengan sistem alir. Produk yang terbentuk dianalisis dengan kromatografi gas-spektrometer massa GC-MS. Produk utama dari HDO anisol yaitu benzena dan toluene. Aktivitas katalis Mo-Co/USY lebih tinggi daripada USY dan termal. Katalis Mo-Co/USY B memiliki selektivitas tertinggi pada produk benzena (15%).

Alchemy: Jurnal Penelitian Kimia, Sep 1, 2016

Soda api (NaOH) telah lama digunakan dalam produksi bioetanol yaitu pada destilasi tahap dua, unt... more Soda api (NaOH) telah lama digunakan dalam produksi bioetanol yaitu pada destilasi tahap dua, untuk meningkatkan kemurnian bioetanol hingga 90 %. Proses destilasi akan menghasilkan limbah cair dengan kadar natrium tinggi yang berdampak buruk bagi tanah. Penelitian ini bertujuan untuk mempelajari penggantian NaOH dengan KOH, dimana diketahui bahwa kalium merupakan salah satu nutrien yang menjaga kesuburan tanah. Perbandingan parameter-parameter termodinamika, kurva kesetimbangan fasa uapcair dan titik azeotrop pada destilasi campuran air-etanol digunakan untuk jika KOH dan NaOH digunakan sebagai aditif. Penelitian ini menggunakan suatu model campuran airetanol pada beberapa variasi komposisi 0-100 % berat etanol. Penambahan elektrolit adalah 0,1 mol elektrolit / berat total campuran etanol-air. Hasilnya menunjukkan bahwa penambahan elektrolit ke dalam campuran air-etanol dapat menghilangkan titik azeotrop dan menyebabkan molekul-molekul etanol lepas dari molekul-molekul air. Entalpi pencampuran antara air-etanol yaitu 239,601 kJ/mol. Entalpi pencampuran menjadi 259.796 kJ/mol and 264.793 kJ/mol setelah penambahan NaOH dan KOH. Hal ini menunjukkan bahwa pencampuran berlangsung secara endotermis dikarenakan perbedaan polaritas molekul air dan molekul etanol. Keberadaan elektrolit bahkan menurunkan interaksi antar molekul-molekul air-etanol. Tetapi pencampuran menyebabkan ketidakteraturan yang menyebabkan perubahan entropi positif dan perubahan energi bebas Gibbs negatif. Hal ini mengindikasikan bahwa pencampuran terjadi secara spontan pada suhu kamar. Sedangkan perubahan entalpi penguapan, ΔH vap , dari campuran air-etanol yaitu 76,229 kJ/mol dan menjadi 235,366 kJ/mol setelah penambahan NaOH, serta berubah menjadi 126,189 kJ/mol setelah penambahan KOH. Hal ini mengindikasikan bahwa keberadaan elektrolit menghambat penguapan air sebagai komponen utama dalam campuran dan menyebabkan molekul-molekul etanol menguap menghasilkan destilat etanol dengan kemurnian tinggi.

IOP conference series, Feb 1, 2017

The non-sulfide catalysts Co-Mo/USY were prepared with three different methods, i.e. co-impregnat... more The non-sulfide catalysts Co-Mo/USY were prepared with three different methods, i.e. co-impregnation and two sequential impregnation procedures. The phases of the synthesized materials and their composition were characterized with X-ray diffraction. Furthermore, the X-ray diffraction patterns were analyzed using Le Bail methods with Rietica software. Finally, an overview of the substitution effect of cobalt and molybdenum on the metal content and acidity of the catalyst were also investigated. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Nucleation and Atmospheric Aerosols, 2022

Jurnal Teknologi, Nov 29, 2022

ZSM5 utilization on a large scale has a problem due to the expensive costs. In this study, the ef... more ZSM5 utilization on a large scale has a problem due to the expensive costs. In this study, the effect of ZSM5 substitution to ZSM5-FA on the crystallinity, specific surface area, morphology, and acidity were studied. Fly ash was purified with HCl then converted into ZSM5-FA by hydrothermal method. XRD, XRF and SAA characterization were carried out to study the purification and ZSM5-FA synthesis. Cu, Mg, and Zr was loaded on ZSM5 and ZSM5-FA by deposition-precipitation to produce CMZrZ and CMZrZ-FA. These materials were characterized by XRD, XRF, SAA, SEM-EDS, and NH3-TPD to study the metals loading and ZSM5 substitution effects. ZSM5-FA was successfully synthesized from fly ash based on the similarity between ZSM5-FA and ZSM5 XRD patterns, the match between ZSM5-FA and ICDD 00-037-0361 XRD patterns and the isotherm curve changes. Cu, Mg, Zr were successfully loaded to ZSM5 and ZSM5-FA with metal oxide as the main phase. The metal loading didn't affect the crystallinity, morphology, porosity, structure but caused a decrease in the specific surface area, total acidity, strong acid sites and an increase in the weak acid sites. The ZSM5 substitution didn't affect the crystallinity, morphology, porosity, acidity, structure but caused an increase in the specific surface area. Abstrak Pemanfaatan ZSM5 sintetik dalam skala besar sering bermasalah karena harganya mahal. Oleh karena itu, pada penelitian ini akan dipelajari pengaruh subtitusi ZSM5 menjadi ZSM5-FA pada material CMZrZ terhadap kristalinitas, specific surface area, morfologi, dan keasaman. Fly ash dimurnikan dengan HCl kemudian diubah menjadi ZSM5-FA dengan metode hidrotermal. Karakterisasi XRD, XRF dan SAA dilakukan untuk mengetahui efek pemurnian dan sintesis ZSM5-FA. Pemuatan Cu, Mg, dan Zr pada ZSM5 maupun ZSM5-FA dilakukan dengan deposisi-presipitasi untuk menghasilkan material CMZrZ dan CMZrZ-FA. Kedua material tersebut dikarakterisasi dengan XRD, XRF, SAA, SEM-EDS, dan NH3-TPD untuk mempelajari efek penambahan logam dan subtitusi ZSM5. ZSM5-FA berhasil disintesis berdasarkan kemiripan spektra XRD ZSM5-FA dengan ZSM5, kecocokan spektra XRD ZSM5-FA dengan ICDD 00-037-0361 (standar ZSM5) dan perubahan bentuk kurva isoterm adsorpsidesorpsi. Logam Cu, Mg, Zr berhasil ditambahkan pada ZSM5 maupun ZSM5-FA dengan fasa utama berupa logam oksida (CuO, MgO, dan ZrO2). Penambahan logam tidak mempengaruhi kristalinitas, morfologi, porositas tetapi menyebabkan penurunan luas permukaan spesifik, keasaman total dan situs asam kuat, serta peningkatan situs asam lemah. Subtitusi ZSM5 tidak mempengaruhi kristalinitas, morfologi, porositas, keasaman tetapi menyebabkan kenaikan luas permukaan spesifik.

Journal of the Australian Ceramic Society, Jul 12, 2022

Indonesian Journal of Chemistry, Jun 14, 2022

Bifunctional catalysts are often used in multiple reactions to synthesize certain products. The c... more Bifunctional catalysts are often used in multiple reactions to synthesize certain products. The catalytic activity of bifunctional catalysts is influenced by parameters such as crystallinity, specific surface area, metal distribution, and morphology. Bifunctional catalysts are manufactured by adding metal to the support. The metal loading to the support often affects these parameters. Therefore, this research was conducted to determine the effect of CuO, MgO, and ZrO 2 addition to HZSM5 on these parameters. The often-used loading method was deposition precipitation. The pH of the metal-support precursors' solution was increased to basic (pH of 8) to deposit the metal on the support. The loading effect was investigated by producing the following materials: CuO/HZSM5, CuO/ZrO 2 /HZSM5, CuO/MgO/HZSM5, and CuO/MgO/ZrO 2 /HZSM5. Each material was characterized using XRD, SAA, SEM, Mapping, EDS, and XRF. The results showed that all metal oxides could be embedded in the HZSM5. The loading of CuO, MgO, and ZrO 2 to HZSM5 did not affect the crystallinity (structure) and morphology, increased the specific surface area, and was evenly distributed inside the pore of HZSM5. Further research is needed to determine the effect of crystallinity, specific surface area, and morphology on other metals and support types.

IOP conference series, Feb 5, 2016

In this research NSDC (composite of Na2CO3-SDC) was prepared by the sol-gel method to produce NSD... more In this research NSDC (composite of Na2CO3-SDC) was prepared by the sol-gel method to produce NSDC1 and also by the ceramic method to produce NSDC2. The prepared NSDC then were analyzed by XRD embedded with Le Bail refinement to study the change of characteristic peaks, their crystal structure, and their cell parameters. Meanwhile, the measurement of impedance was conducted to study the electrical conductivity of the prepared materials. A single cell was prepared by coating NSDC-L (a composite of NSDC with Li0.2Ni0.7Cu0.1O2) on both surfaces of NSDC. The NSDC-L was used as anode and cathode. The ionic conductivity of NSDC1 and NSDC2 at 400 oC are 4.1109 x 10-2 S.cm-1 and 1.6231 x 10-2 S.cm-1, respectively. Both electrolytes have ionic conductivity higher than 1 x 10-4 S.cm-1, therefore, can be categorized as good electrolyte [1]. However, the NSDC1 shows electrodeelectrolyte conduction. It indicates the existence of electronic migration from electrolyte- electrode or vice versa. Those may cause a short circuit during fuel cell operation and will reduce the fuel cell performance fastly. The single cell tests were conducted at 300, 400, 500 and 600 °C. The single fuel cell with NSDC1 and NSDC2 as electrolyte show maximum power density at 400 °C with the power density of 3.736 x 10-2 mW.cm-2 and 2.245 x 10-2 mW.cm-2, respectively.

$Research paper thumbnail of Derivation and constants determination of the Freundlich and (fractal) Langmuir adsorption isotherms from kinetics$

IOP conference series, Mar 1, 2018

The Freundlich adsorption isotherm is mostly presented as an empirical equation and the (fractal)... more The Freundlich adsorption isotherm is mostly presented as an empirical equation and the (fractal) Langmuir adsorption isotherm is derived from kinetics. However, their constants are determined by thermodynamic approach. As yet, both are used as an independent tool for determining the type of adsorption, just physical or chemical adsorption. This study aims to introduce an alternative way of driving Freundlich adsorption isotherm from kinetics, to elaborate its relation with the (fractal) Langmuir adsorption isotherm, and to determine their constants simultaneously by kinetics approach. An alternative way of determining the constants in both isotherm equations by kinetics approach was introduced. The results were then compared with that obtained by the conventional method. The study is theoretical but the validity of determination technique is based on the statistical tests on data adapted from literature. The Freundlich adsorption isotherm is introduced; the isotherm is the (fractal) Langmuir adsorption isotherm at relatively low concentration. It is irrelevant to use both adsorption isotherm separately. The new method is more reliable and its represent the reaction.

Australian Journal of Chemistry, May 20, 2022

The electrical properties of graphene doped with graphite and N-pyridine and their interaction wi... more 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.

IOP conference series, Apr 1, 2018

Natural zeolite is abundantly available in Indonesia and well distributed especially in the volca... more Natural zeolite is abundantly available in Indonesia and well distributed especially in the volcano area like Java, Sumatera, and Sulawesi. So far, natural zeolite from Klaten, Central Java is one of the most interesting zeolites has been widely studied. This research aims to know the effect of seed-assisted synthesis under a hydrothermal condition at 120 °C for 24 hours of Klaten's zeolite toward the structural change and phase transformation of the original structure. According to XRD and XRF analysis, seed-assisted synthesis through the addition of aluminosilicate mother solution has transformed Klaten's zeolite which contains (mordenite and clinoptilolite) into analcime type with decreasing Si/Al ratio from 4.51 into 1.38. Morphological analysis using SEM showed the shape changes from irregular into spherical looks like takraw ball in the range of 0.3 to 0.7 micrometer. Based on FTIR data, structure of TO4 site (T = Si or Al) was observed in the range of 300-1300 cm-1 and the occupancy of Brønsted acid site as OH stretching band from silanol groups was detected at 3440-3650 cm-1. Nitrogen adsorptiondesorption analysis confirmed that transformation Klaten's zeolite into analcime type has decreased the surface area from 55.41 to 22.89 m 2 /g and showed inhomogeneous pore distribution which can be classified as micro-mesoporous aluminosilicate materials.

Molekul: Jurnal Ilmiah Kimia, Mar 20, 2023

Defects in graphene alter its structure, electrical characteristics, and interaction with K + ion... more 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.

Journal of physics, Mar 1, 2022

ZSM-5 and analcime were successfully synthesized from coal fly ash using hydrothermal method in a... more ZSM-5 and analcime were successfully synthesized from coal fly ash using hydrothermal method in alkaline solution. The fly ash used was taken from the Paiton PLTU, one of the largest steam power plants in Indonesia. The fly ash was purified using sulphuric acid for 30 minutes and it was found that it has 17.7 wt.% of Si content and 2.79 wt.% of Al content. The zeolite synthesis was carried out in a hydrothermal reactor at 160 oC and 3 bar for 48 hours both with and without alumina addition. Subsequently, the zeolite produced was then calcined and characterized using X-ray diffraction (XRD) analysis. The results showed that ZSM-5 crystals were obtained from the hydrothermal process without alumina addition. On the other hand, the addition of alumina has a large impact on the hydrothermal process, which formed analcime crystals as the final product. Furthermore, the ZSM-5 and analcime produced have great correspondence to ICSD (Inorganic Crystal Structure Database) standards (no. 61010 for ZSM-5 and no. 34877 for analcime).

IOP conference series, Mar 1, 2018

This research aims to determine the best catalyst and carrier gas in anisole deoxygenation reacti... more This research aims to determine the best catalyst and carrier gas in anisole deoxygenation reaction. The reaction was carried out over a flow system with a variation of catalyst CoMo A (CoMo/USY reduction), CoMo B (CoMo/USY oxidation-reduction), and CoMo C (CoMo/ZAA oxidation-reduction). In addition, variation of carrier gas nitrogen and hydrogen was investigated. The result was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). The deoxygenation anisole result showed that CoMo A catalyst with hydrogen as the carrier gas has the highest total product yield (50.72 %), intermediate product yield (38.49 % in phenol and 6.99 % in benzaldehyde), and deoxygenation yield (5.24 %). The CoMo C catalyst exhibited the most selective deoxygenation product. The nitrogen carrier gas with the CoMo C catalyst has the best selectivity of benzene product (93.92 %).

Molekul: Jurnal Ilmiah Kimia, May 16, 2016

Electro-synthesis of Metal-Organic Frameworks types of MIL-100(Fe) (MIL = Material Institute of L... more Electro-synthesis of Metal-Organic Frameworks types of MIL-100(Fe) (MIL = Material Institute of Lavoisier) in ethanol: water (1: 1) with electrolyte TBATFB 0.1 M has been optimized by varying voltage (12, 13, 14 and 15 Volt) and temperature (room temperature, 40, 60 and 80 °C). The product showed light brown powder which upon activation becomes dark brown. Optimum condition achieved during use voltage of 15 Volts and at a temperature of 40 °C with 33% yield. The obtained material was characterized by XRD and compared to CCDC 640536 simulated patterns to confirm the phase purity of the product. As comparison hydrothermal and reflux method have been carried out. Characterization by FTIR has also undertaken to ensure the coordination between the metal cation (Fe 3+) and the BTC ligand (BTC = 1,3,5-Benzene Tri Carboxylate). Meanwhile pore analysis using SAA confirmed that MIL-100(Fe) obtained by electrolysis method has a BET surface area reached till 569.191 m²/g with a total pore volume of 0.4540 cc/g and an average pore diameter reached 16 Å. Based on SEM analysis, morphology material show particle size between 0.4-8.6 μm and has a thermal stability up to 350 °C according thermo-gravimetric analysis. Due to the presence of Lewis acid sites on Fe-trimeric unit, porosity features on MIL-100(Fe) and a fairly high thermal stability, this material is potentially used as the host material for the catalyst in the conversion reactions model for green diesel production.

Evergreen, Mar 1, 2024

Ingeniería e Investigación/Ingeniería e Investigación, Feb 23, 2024

Evergreen, Jun 1, 2022

Jurnal Rekayasa Proses, Mar 24, 2023

Jurnal Penelitian Saintek, Mar 1, 2015

Alchemy: Jurnal Penelitian Kimia, Sep 1, 2016

IOP conference series, Feb 1, 2017

Nucleation and Atmospheric Aerosols, 2022

Jurnal Teknologi, Nov 29, 2022

Journal of the Australian Ceramic Society, Jul 12, 2022

Indonesian Journal of Chemistry, Jun 14, 2022

IOP conference series, Feb 5, 2016

$Research paper thumbnail of Derivation and constants determination of the Freundlich and (fractal) Langmuir adsorption isotherms from kinetics$

IOP conference series, Mar 1, 2018

Australian Journal of Chemistry, May 20, 2022

IOP conference series, Apr 1, 2018

Molekul: Jurnal Ilmiah Kimia, Mar 20, 2023

Journal of physics, Mar 1, 2022

IOP conference series, Mar 1, 2018

Molekul: Jurnal Ilmiah Kimia, May 16, 2016