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Journal : Indonesian Journal of Chemistry

Oxidation of Cyclohexane to Cylohexanol and Cyclohexanone Over H4[a-SiW12O40]/TiO2 Catalyst Lesbani, Aldes; Fatmawati, Fatmawati; Mohadi, Risfidian; Fithri, Najma Annuria; Rohendi, Dedi
Indonesian Journal of Chemistry Vol 16, No 2 (2016)
Publisher : Universitas Gadjah Mada

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Abstract

Oxidation of cyclohexane to cyclohexanol and cyclohexanone was carried out using H4[a-SiW12O40]/TiO2 as catalyst. In the first experiment, catalyst H4[a-SiW12O40]/TiO2 was synthesized and characterized using FTIR spectroscopy and X-Ray analysis. In the second experiment, catalyst H4[a-SiW12O40]/TiO2 was applied for conversion of cyclohexane. The conversion of cyclohexane was monitored using GC and GCMS. The results showed that H4[a-SiW12O40]/TiO2 was successfully synthesized using 1 g of H4[a-SiW12O40] and 0.5 g of TiO2. The FTIR spectrum showed vibration of H4[a-SiW12O40] appeared at 771-979 cm-1 and TiO2 at 520-680 cm-1. The XRD powder pattern analysis indicated that crystallinity of catalyst still remained after impregnation to form H4[a-SiW12O40]/TiO2. The H4[a-SiW12O40]/TiO2 catalyst was used for oxidation of cyclohexane in heterogeneous system under mild condition at 2 h, 70 °C, 0.038 g catalyst, and 3 mL hydrogen peroxide to give cyclohexanone as major product.
PREPARATION OF CALCIUM OXIDE FROM Achatina fulica AS CATALYST FOR PRODUCTION OF BIODIESEL FROM WASTE COOKING OIL Lesbani, Aldes; Tamba, Palita; Mohadi, Risfidian; Fahmariyanti, Fahmariyanti
Indonesian Journal of Chemistry Vol 13, No 2 (2013)
Publisher : Universitas Gadjah Mada

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Abstract

Preparation of calcium oxide from Achatina fulica shell has been carried out systematically by decomposition for 3 h at various temperatures i.e. 600, 700, 800 and 900 °C. Formation of calcium oxide was characterized using XR diffractometer. The calcium oxide obtained with the optimum temperature decomposition was characterized using FTIR spectroscopy to indicate the functional group in the calcium oxide. The results showed that XRD pattern of materials obtained from decomposition of Achatina fulica shell at 700 °C is similar with XRD pattern of calcium oxide standard from Joint Committee on Powder Diffraction Standards (JCPDS). The IR spectra of calcium oxide appear at wavenumber 362 cm-1 which is characteristic of CaO vibration. Application of calcium oxide from Achatina fulica shell for synthesis of biodiesel from waste cooking oil results in biodiesel with density are in the range of ASTM standard.
Conversion of Cyclohexanone to Adipic Acid Catalyzed by Heteropoly Compounds Lesbani, Aldes; Fitriliana, Fitriliana; Mohadi, Risfidian
Indonesian Journal of Chemistry Vol 15, No 1 (2015)
Publisher : Universitas Gadjah Mada

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Abstract

Conversion of cyclohexanone to adipic acid using hydrogen peroxide as green oxidant catalyzed by heteropoly compounds i.e. H5[a-BW12O40] H4[a-SiW12O40] and H4[a-PVMo11O40] has been carried out systematically in one pot synthesis under mild condition. The product of adipic acid was characterized using GC-MS, FT-IR, 1H-NMR and 13C-NMR spectroscopy. The results show that cyclohexanone could be converted into adipic acid by using H5[a-BW12O40] H4[a-SiW12O40] as catalysts, whereas H4[a-PVMo11O40] did not shows catalytic activity in this reaction. The effect of reaction time gave adipic acid 41% for reaction time 7 h. The yield of adipic acid was 30% with melting point 149-151 °C. The oxidation temperature at 100 °C gave the highest adipic acid 48% was obtained. The FT-IR, 1H-NMR and 13C-NMR spectra of the product are well agreed to the adipic acid standard.
SORPTION-DESORPTION MECHANISM OF Zn(II) AND Cd(II) ON CHITIN Santosa, Sri Juari; Narsito, Narsito; Lesbani, Aldes
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

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Abstract

This study reports the results of the elucidation of the sorption-desorption mechanism of Zn(II) and Cd(II) on chitin through the determination of capacity, energy, and rate constant of sorption as well as the investigation of their desorption properties in NaCl and Na2EDTA solutions. The chitin was isolated through deproteination followed by demineralization of crab (Portunus pelagicus Linn) shell using NaOH solutions. The sorption of both metal ions followed the Langmuir isotherm model, resulting the sorption capacities of 3.2 x 10-4 and 2.8 x 10-4 mol g-1 for Zn(II) and Cd(II), respectively, and sorption energies of 15.1 kJ mol-1 for Zn(II) and 17.9 kJ mol-1 for Cd(II). It was also observed that Zn(II) was sorbed slightly faster than Cd(II) with first order sorption rate constants of 2.82 x 10-3 min-1 for Zn(II) and 2.61 x 10-3 min-1 for Cd(II). The result of the desorption experiment showed that Cd(II) and especially Zn(II) could only be exchanged by Na(I) after desorbing those metal ions by strong chelating agent of EDTA2-. The easier desorption of Zn(II) than Cd(II) by EDTA2- must be attributed by the smaller sorption energy of Zn(II) and by harder acid property of Zn(II) than Cd(II) as EDTA2- contained hard electron donor elements.   Keywords: sorption, desorption, chitin, Zn(II), Cd(II)
Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst Mohadi, Risfidian; Teresia, Lusi; Fithri, Najma Annuria; Lesbani, Aldes; Hidayati, Nurlisa
Indonesian Journal of Chemistry Vol 16, No 1 (2016)
Publisher : Universitas Gadjah Mada

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Abstract

Catalyst (NH4)6[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH4)6[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH4)6[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH4)6[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH4)6[b-P2W18O62]/Ta after impregnation was higher than (NH4)6[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH4)6[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH4)6[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH4)6[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.
Synthesis and Characterization of Chitosan Linked by Methylene Bridge and Schiff Base of 4,4-Diaminodiphenyl Ether-Vanillin Fatoni, Ahmad; Hariani, Poedji Loekitowati; Hermansyah, Hermansyah; Lesbani, Aldes
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

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Abstract

The synthesis chitosan-methylene bridge-Schiff base of 4,4-diaminodiphenyl ether-vanillin using casting method has been done. The aims of this research were modification chitosan with Schiff base of 4,4-diaminodiphenyl ether-vanillin, formaldehyde and its characterization using FTIR spectroscopy, SEM analysis, 1H-NMR and X-Ray Diffraction analysis. The first step was a synthesis of modified chitosan between chitosan and Schiff base of 4,4-diaminodiphenyl ether-vanillin. The second step was chitosan modified Schiff base of 4,4-diaminodiphenyl ether-vanillin then reacted with formaldehyde through casting method. The result showed that chitosan can be modified with Schiff base of 4,4-diaminodiphenyl ether-vanillin and formaldehyde and this modified chitosan can be linked by methylene bridge (-NH-CH2-NH-) and had azomethine group (-C=N-). The functional group of –C=N in modified chitosan before and after adding formaldehyde appeared at a constant wavenumber of 1597 cm-1. The functional group C-N in methylene bridge detected at 1388 and 1496 cm-1. The chitosan-Schiff base of 4,4-diaminodiphenyl ether-vanillin and Chitosan-methylene bridge-Schiff base of 4,4-diaminodiphenyl ether-vanillin had index crystalline (%)16.04 and 25.76, respectively. The chemical sift of signal proton azomethine group (-C=N-) in modified chitosan detected at 8.44–8.48 and 9.77 ppm. Proton from methylene bridge in modified chitosan appeared at 4.97–4.99 and 3.75 ppm. Surface morphology chitosan-methylene bridge-Schiff base of 4,4-diaminodiphenylether-vanillin had dense surfaces, mostly uniform and regular in shape.
Adsorption of Cadmium(II) Using Ca/Al Layered Double Hydroxides Intercalated with Keggin Ion Taher, Tarmizi; Irianty, Yunita; Mohadi, Risfidian; Said, Muhammad; Andreas, Roy; Lesbani, Aldes
Indonesian Journal of Chemistry Vol 19, No 4 (2019)
Publisher : Universitas Gadjah Mada

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Abstract

Ca/Al layered double hydroxides (Ca/Al LDH) was synthesized using co-precipitation method following calcination at 800 °C and was intercalated with Keggin ion [α-SiW12O40]4– to form intercalated Ca/Al LDH. Materials were characterized using XRD and FTIR spectrophotometer. Furthermore, materials were used as an adsorbent of cadmium(II) from solution. The results showed that layer material was formed completely after calcination which was indicated at diffraction 20° due to loss of water in the interlayer space. Ca/Al LDH after calcination was intercalated with [α-SiW12O40]4– ion and interlayer distance was increased from 4.25 to 4.41 Å showed that intercalation process was successfully conducted. Adsorption of cadmium(II) using Ca/Al LDH was conducted at pH 9 and intercalated Ca/Al LDH at pH 8 showed that intercalated material has slightly faster than Ca/Al LDH without intercalation probably due to slightly increasing interlayer distance of Ca/Al LDH after intercalation. The adsorption capacity of intercalated Ca/Al LDH was higher than Ca/Al LDH without intercalation at the temperature range of 30–50 °C.