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

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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%).