Wega Trisunaryanti
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281, Indonesia

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Hydrochloric Acid and/or Sodium Hydroxide-modified Zeolite Y for Catalytic Hydrotreating of α-Cellulose Bio-Oil Jason Mandela; Wega Trisunaryanti; Triyono Triyono; Mamoru Koketsu; Dyah Ayu Fatmawati
Indonesian Journal of Chemistry Vol 21, No 4 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55645

Abstract

The zeolite Y had been successfully modified by HCl and/or NaOH treatment. The modification of zeolite Y was performed by leaching the protonated zeolite Y (HY) in HCl solution (0.1 and 0.5 M) at 70 °C for 3 h resulting in DY0.1 and DY0.5. Subsequently, HY, DY0.1, and DY0.5 zeolites were immersed in 0.1 M NaOH for 15 min at room temperature resulting in AHY, ADY0.1, and ADY0.5. All samples were analyzed for acidity, crystallinity, Si/Al ratio, morphology, and textural properties. The catalytic performance of all samples was investigated in hydrotreating of α-cellulose bio-oil with a catalyst/feed weight ratio of 1/30. The HCl and NaOH treatment led to the decrease of the zeolite Y crystallinity and the increase of the zeolite Y average pore diameter (i.e., the mesopore distribution). The ADY0.5 gave the highest mesopore distribution, which was 43.7%, with an average pore diameter of 4.59 nm. Moreover, both of the treatments were found to increase the Si/Al ratio that caused the decrease of zeolites Y acidity. All the zeolite Y samples gave better catalytic activity to produce liquid products after being treated by NaOH. The sample ADY0.5 managed to produce 6.12% of 1-isopropyl-2,4-dimethylbenzene that has good potential to be processed into fuel.
Simple and Green Preparation of ZnO Blended with Highly Magnetic Silica Sand from Parangtritis Beach as Catalyst for Oxidative Desulfurization of Dibenzothiophene Wega Trisunaryanti; Safa Annissa Novianti; Dyah Ayu Fatmawati; Triyono Triyono; Maria Ulfa; Didik Prasetyoko
Indonesian Journal of Chemistry Vol 22, No 2 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.69938

Abstract

Simple and green preparation of ZnO blended with Parangtritis beach sand (BS) catalysts for oxidative desulfurization of dibenzothiophene (ODS-DBT) has been conducted. The ZnO-BS catalysts were prepared by blending ZnO with beach sand under a weight ratio of 1:1, 1:2, and 1:4, and then heated by microwave (MW) at 540 watts for 30 min, resulting in BS-MW, ZnO-MW, ZnO-BS-1-MW, ZnO-BS-2-MW, and ZnO-BS-4-MW, respectively. As a comparison, the ZnO-BS-1 was also heated by oven at 100 °C for 30 min produced ZnO-BS-1-OV. Each product was characterized by XRF, XRD, FTIR, acidity test by NH3 vapor adsorption, SAA, SEM-EDX, TEM, and magneticity test by an external magnetic field. Furthermore, each material was applied for ODS-DBT, and its product was analyzed by UV-Vis spectrophotometer and FTIR. The results showed that ZnO-BS-1-OV had the highest acidity of 2.3486 mmol/g and produced the highest DBT removal efficiency through the ODS reaction of 81.59%. The use of catalysts in ODS-DBT does not affect the main structure of the treated fuel. Therefore, the combination of ZnO with BS can provide good performance in ODS activity and facilitate the separation of catalysts after the reaction due to its magnetic iron oxide content.
Synthesis of Mesoporous Silica from Beach Sand by Sol-Gel Method as a Ni Supported Catalyst for Hydrocracking of Waste Cooking Oil Siti Salamah; Wega Trisunaryanti; Indriana Kartini; Suryo Purwono
Indonesian Journal of Chemistry Vol 22, No 3 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.70415

Abstract

Mesoporous silica (MS) supported by nickel was synthesized from Parangtritis beach sand and assessed for its activity and selectivity as catalysts in hydrocracking waste cooking oil into biofuel. The synthesis of MS was done by the sol-gel method. Ni/MS catalysts using Ni weight variations of 1, 5, and 10 wt.% were denoted as Ni/MS1, Ni/MS5, and Ni/MS10 and were compared to standard mesoporous silica (Ni/SBA-15). The catalysts were characterized using FTIR, XRD analysis, N2 gas sorption analysis, SEM-EDX, and TEM. Catalyst Ni/MS1, Ni/MS5, Ni/MS10, and Ni/SBA-15 have specific surface areas of 130.5, 195.9, 203.9, and 381.2 m2/g and the average pores of 12.30, 9.80, 11.12, and 8.70 nm, respectively. The hydrocracking was run four times to evaluate the catalyst reusability. The hydrocracking WCO has 95.8, 82.4, and 85.2%, respectively. While Liquid fractions produced were 38.8, 43.2, and 50.2 wt.%, each of which contains gasoline of 37.09, 39.76, and 44.27 wt.%, Ni/MS10 has the highest liquid products of 50.2 wt.% and was selective to gasoline fractions up to 44.27%. Therefore, the catalyst synthesized from Parangtritis beach sand is selective for gasoline-fraction hydrocarbon and has hydrocracking activity up to 4 runnings.
Role of Temperature and Time Exposure for Controlled and Accelerated Synthesis of Graphene Oxide Using Tour Method Uswatul Chasanah; Wega Trisunaryanti; Haryo Satriya Oktaviano; Triyono Triyono; Dyah Ayu Fatmawati
Indonesian Journal of Chemistry Vol 22, No 5 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.71817

Abstract

Synthesis of graphene oxide (GO) with the Tour method has been studied. In this procedure, phosphoric acid was mixed with sulfuric acid in the ratio of 1:9, and then potassium permanganate and graphite with the ratio of 6:1 was added in an ice bath at the variation of oxidation times of 1, 7 and 24 h and temperatures of 40, 50 and 60 °C. The GOs were characterized by UV–Visible spectroscopy, Fourier Transform InfraRed (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), and Transmission Electron Microscopy (TEM). The results show that the GO oxidized at 40 °C for 7 h (GO-7-40) has been successfully formed indicating that GO-7-40 is the most efficient GO. The GO-7-40 is characterized by a peak at 2θ = 10.89° in the XRD diffractogram, resulting calculation of the average distance between graphene layer (d) of 0.81 nm. The average number of graphene layers (n) is 4, the oxidation level (C/O) is 1.50 according to EDX data, λmax at 226 nm attributes to π→π* transitions of C=C bond in UV-Vis spectrum, and the functional groups such as O-H, C=C, C-OH, and C-OC are observed in FT-IR spectrum.
Microwave-Assisted Chemical Co-reduction of Pd Nanoparticles Anchored on Reduced Graphene Oxide with Different Loading Amounts Dyah Ayu Fatmawati; Triyono Triyono; Wega Trisunaryanti; Uswatul Chasanah
Indonesian Journal of Chemistry Vol 22, No 5 (2022)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.73206

Abstract

Microwave-assisted Palladium/Reduced Graphene Oxide (Pd/RGO) synthesis was effectively carried out in this study, which looked at the effects of different Pd loading weights in Graphene Oxide (GO) on its physicochemical qualities. The Tour technique was used to make GO, with a KMnO4:graphite weight ratio of 3.5. Meanwhile, Pd/RGO was synthesized utilizing the in-situ reduction method of one-pot synthesis with ascorbic acid as the green reducing agent, yielding Pd-0.5/RGO, Pd-1.0/RGO, and Pd-2.0/RGO, respectively, with variations in Pd loading weight of 0.5, 1.0, and 2.0%. XRD, FTIR, SAA, SEM-EDX, and TEM were used to examine all material characterizations. As a result, Pd-1.0/RGO had the largest surface area of 65.168 m2/g among the Pd-based materials, with a pore volume of 0.111 cc/g, the pore diameter of 3.316 nm, Pd crystallite size of 28.29 nm, RGO nanostructure dimension of 3.37 × 28.53 nm, and reduction level (C/O) of 3.02. This material also contains specific functional groups, including O-H, C-H, CO2, C=C, C=O, and C-O, based on FTIR spectra. Therefore, optimal weight loading of metal on the surface of the supporting material will provide a large material surface area. Increasing the surface area of the material improves its performance as a catalyst.
Effect of Acetic Acid and/or Sodium Hydroxide Treatment towards Characters of Wonosari Natural Zeolite for Hydrotreatment of Castor Oil into Biofuel Triyono Triyono; Wega Trisunaryanti; Iip Izul Falah; Lailatul Rahmi
Indonesian Journal of Chemistry Vol 23, No 2 (2023)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.73746

Abstract

Natural zeolite (ZA) obtained from Wonosari, Indonesia, was treated with acetic acid (ZAA) or NaOH (ZAB), and the combination of both treatments (ZAAB) in order to increase the Si/Al ratio and catalytic performance on hydrotreatment of castor oil. The Si/Al ratio of ZA increased after the combination of acetic acid and NaOH treatment. The change of the Si/Al ratio was observed in the FTIR spectra as the shifting of internal asymmetric stretching vibration of T−O−T at 1032-1100 cm−1. The XRD profile of ZA was maintained after being subjected to treatments, and ZAB exhibited the lowest crystallinity. The surface area of the ZA after treatment is in the order ZAA < ZA < ZAAB < ZAB. The ZAB catalyst having the highest surface area (19.144 m2 g−1) showed the highest catalytic activity on the hydrotreatment of castor oil with a liquid fraction of 55.1 wt.% and selectivity towards the hydrocarbon compounds of 22.40 wt.%.
Characteristic and Performance of Ni, Pt, and Pd Monometal and Ni-Pd Bimetal onto KOH Activated Carbon for Hydrotreatment of Castor Oil Wega Trisunaryanti; Triyono Triyono; Iip Izul Falah; Dwi Bagus Wicaksono; Satriyo Dibyo Sumbogo
Indonesian Journal of Chemistry Vol 24, No 1 (2024)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.84640

Abstract

The preparation of highly efficient hydrotreating catalysts has presented a significant challenge in the field of catalysis. In this study, chemically activated carbon (AC) was prepared using potassium hydroxide (KOH) as an activator and Merbau wood as a lignocellulosic source for the AC. The AC was then impregnated with mono-metallic species (nickel, platinum, and palladium) as well as a bimetallic NiPd combination. The results revealed that the optimal KOH impregnation weight ratio was determined to be 2:1, resulting in a remarkably high iodine value of 751.94 mg/g. Subsequently, AC was employed as a support material for the hydrotreating of castor oil. Among the catalysts tested, the NiPd/AC catalyst demonstrated superior performance, yielding a liquid fraction comprising 88.80 wt.%. Within this fraction, C5-C12 hydrocarbons accounted for 15.16 wt.%, alcohol compounds constituted 71.69 wt.%, while the remaining 0.87 wt.% consisted of other components. Furthermore, the NiPd/AC catalyst exhibited remarkable stability, as its performance remained largely unchanged even after being used three times consecutively. This finding suggests that coking had minimal impact on the active sites of the mentioned catalyst, indicating its robustness and potential for prolonged application.
Modification of Natural Zeolite from Klaten, Indonesia Using Ammonium Chloride by Ion-Exchange and Its Application as Catalyst in Ethanol Dehydration to Produce Diethyl Ether Zaira Adila; Wega Trisunaryanti; Triyono Triyono
Indonesian Journal of Chemistry Vol 24, No 2 (2024)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.90279

Abstract

Modification of a natural zeolite from Klaten, Indonesia, as a catalyst in the dehydration of ethanol to produce diethyl ether (DEE) has been conducted. Raw Klaten natural zeolite (ZA) was modified using 1 and 2 M of an ammonium chloride solution for 24 h while stirring for 18 h, then calcined at 500 °C for 5 h under N2 gas flow produced HZA1 and HZA2 catalyst, respectively. The catalysts were characterized using XRD, BET surface area, SEM-EDX, XRF, FTIR and gravimetric acidity test using ammonia-based vapor. The dehydration process was conducted under variations of temperature (200, 250, and 300 °C) and catalyst mass of 0.1, 0.2, and 0.4 g for 20 mL of 96% ethanol. The HZA1 catalyst produced the highest yield of DEE (2.41%) at 250 °C and 0.1 g catalyst. This catalyst showed needle-like of 66.22 nm crystal size, consisting of 32.57% mordenite, the highest surface area (48.32 m2/g), crystallinity (32.93%) and Brønsted acid sites (2.75 mmol/g), the lowest pore diameter (1.77 nm) and Si/Al mol ratio (4.03). The HZA1 catalyst can be used repetitively and produced DEE yield at the second and third runs (2.40 and 2.61%).