Articles
ISOTERM ADSORPSI-DESORPSI DAN POROSITAS KATALIS Ag-TiO 2 /ZEOLIT
Hasanudin, Hasanudin;
Rachmat, Addy
Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam Sainmatika Volume 7 No. 2 Desember 2010
Publisher : Faculty of Mathematics and Natural Science, Universitas PGRI Palembang
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DOI: 10.31851/sainmatika.v7i2.10
ABSTRAKPenelitian tentang Isoterm Adsorpsi-Desorpsi dan Porositas Katalis Ag âTiO 2 /Zeolit telah dilakukan. Katalis ini dibuat dengan penambahan oksida logam TiO 2 dan impregnasi logam Ag dengan variasi jumlah logam Ag yaitu 1%, 10%, 20%. Karakterisasi katalis meliputi pola topografi dengan Scanning Electron Microscope (SEM) dan analisis isoterm adsorpsi dengan menggunakan Gas Sorption Analyzer.Tipe isoterm adsorpsi yang terbentuk berdasarkan klasifikasi BDDT adalah tipe II dan isoterm desorpsi yang terbentuk berdasarkan klasifikasi BET adalah tipe C. Hasil penelitian menunjukkan bahwa adanya pori yang membesar akibat penambahan logam TiO 2 sehingga meningkatkan luas permukaan spesifik, total volume pori, dan jari-jari pori rata-rata katalis. Pengaruh impregnasi logam Ag pada katalis mampu menurunkan luas permukaan katalis senilai 129,94% dan menurunkan total volume pori senilai 34,81% namun dapat meningkatkan jari-jari pori rata-rata senilai 70,56%.Kata kunci: Zeolit, porositas, katalis
A Review on Production of Hydrogen from Renewable Sources and Applications for Fuel Cell Vehicles
Rohendi, Dedi;
Rahmah, Dea;
Yulianti, Dwi;
Amelia, Icha;
Sya'baniah, Nyimas;
Syarif, Nirwan;
Rachmat, Addy
http://dx.doi.org/10.31427/IJSTT.2018.1.2.5
Publisher : Unijourn Publisher
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Hydrogen gas is an energy carrier that has many advantages, including energy density for high mass and environmentally friendly. Hydrogen can be produced from various sources by numerous methods. Hydrogen production from renewable sources is interesting, due to the sustainable and inexpensive supply of the raw materials. Among the sources of renewable raw materials for hydrogen production are water and biomass with various production methods. It consists of the electrolysis of water with acidic and basic conditions, as well as thermochemical and biochemical biomass conversion.
Photodegradation of Permethrin using Photocatalyst Montmorillonite-TiO2
Addy Rachmat;
Muhammad Said;
Fatma Fatma;
Hardi Aji Badarwi;
A.M. Ramadhan
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 1, No 1 (2016): February 2016
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v1.i1.01
Photocatalyst Montmorillonite-TiO2 was synthesized using template CTAB and natural clay for degradation of Permethrin. The porosity and crystalline phase of catalyst were evaluated using N2 sorption analyzer and XRD diffraction. Permethrin photodegradation was optimized by varying reactant volume, irradiation time and initial concentration. Montmorillonite enhanced by CTAB showed typical porosity i.e. specific surface area, pore radii and pore volume for layer material. It properties decreased as this host material was impregnated with TiO2. XRD diagram indicated that space between layers of Montmorillonite expanded up to 4.7 Å. The diffractogram also confirmed that TiO2 formed an Anatase phase instead of Rutile. Photodegradation conducted at several condition showed relatively low photocatalytic activity. The highest photodegradation was achieved at 50 mL of Permethrin with initial concentration 10 ppm and 100 minutes’ irradiation. Keywords: Permethrin, Photodegradation, Montmorillonite-TiO2
Characterization of Electrode with Cu2O-ZnO/C and Pt-Ru/C Catalyst for Electrochemical Reduction CO2 to CH3OH
Dea Radestia Rahmah;
Dedi Rohendi;
Nirwan Syarif;
Addy Rachmat;
Nyimas Febrika Sya'baniah;
Dwi Hawa Yulianti
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 6, No 1 (2021): February 2021
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v6.i1.08
Electrode characterization has been carried out with Cu2O-ZnO/C and Pt-Ru/C catalysts to convert carbon dioxide to methanol. Characterization are carried out with XRD analysis, Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS). The electrodes are made by distributing Cu2O-ZnO/C and/or Pt-Ru/C catalyst by spraying method. The results of XRD analysis showed that the characteristic peak of platinum was 2θ = 39.7⁰ - 40.74⁰ with an intensity of 970 cps and 1384 cps and the diffraction peak of Ru oxide was found at 47.02⁰ with an intensity of 923 cps. The peak of Cu2O characteristics appeared at 36.12⁰ with an intensity of 88 cps and the peak for ZnO characteristics at 68.2⁰ with an intensity of 13 cps. The test results with the cyclic voltammetry method showed that the electrode with a Cu2O-ZnO/C catalyst obtained the highest ECSA value which was 26.044 cm2/g, with an electrical conductivity value of 3.4 x 10-3 S/cm and a total real resistance of 5.9425 Ω .
Performance Test of Membrane Electrode Assembly in DAFC using Mixed Methanol and Ethanol Fuel with Various Volume Comparison
Dwi Hawa Yulianti;
Dedi Rohendi;
Nirwan Syarif;
Addy Rachmat
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 4, No 3 (2019): October 2019
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v4.i3.139
Direct Alcohol Fuel Cell (DAFC) performance is influenced by electrocatalysis reactions that occur in Membrane Electrode Assembly (MEA). In this study, MEA was made with Pt-Ru/C (anode) and Pt/C (cathode) catalysts. The results of the electrode characterization with XRD showed a carbon peak at 26.63° and Ru at 40.58°. Based on the results of Cyclic Voltammetry (CV) measurements, the Electrochemical Surface Area (ECSA) electrode value is known to be 373.601 cm2/mg. Meanwhile, the impedance value is 4.315 Ω and the electrical conductivity value is 6.61x10-4 S/cm. MEA testing using MeOH 3 M fuel produces Open Circuit Voltage (OCV) of 0.650 V. Meanwhile, MEA performance testing uses a mixture of methanol and ethanol 2 M in loading conditions obtained the best mixture of fuel composition is methanol: ethanol = 90:10 with a maximum power density of 4.34 mW/cm2 and is able to maintain the voltage at 0.649 V under conditions of 6.875 mA/cm2. The results also showed that the volume of ethanol which was too high resulted in a decrease in cell performance in the fuel mixture caused by the competition of adsorption between competing methanol and ethanol occupying the active site of the catalyst.Keywords: DAFC, fuel cell, Pt-Ru/C, ethanol, methanol, Open Circuit Voltage
Preparation and Characterization of Ti-Co/C catalyst for PEMFC Cathode
Nurmalina Adhiyanti;
Dedi Rohendi;
Nirwan Syarif;
Addy Rachmat
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 6, No 3 (2021): October 2021
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v6.i3.109
A Ti-Co/C catalyst was prepared using impregnation-reduction method and characterized using cyclic voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) methods. This study aimed to compare the result between matrix carbon Vulcan XC-72R and Dots carbon which was applied to Ti-Co/C catalyst, also to compare the method of coating catalyst on GDL layer were Doctor Blade and spraying methods. The result was confirmed that Ti-Co/C with the ratio of Ti:Co 50:50, using Dots carbon as its matrix and spraying method preparation has ECSA value and conductivity respectively 28.72 cm2/g and 0.1688 x 10-3 S/cm, those were the highest value than another method. The conclusion of this study was non-platinum catalyst Ti-Co/C which used Dots carbon as a matrix and the spraying method showed a good response as a cathode catalyst of PEMFC
Hydrogen Adsorption/desorption on lithium Alanat Catalyzed by Ni/C for Sustainable Hydrogen Storage
Icha Amelia;
Dedi Rohendi;
Addy Rachmat
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 6, No 2 (2021): June 2021
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v6.i2.59
LiAlH4 alloy has been believed to have the potential to become one of the hydrogen storages with high storage capacity. In this research, the formation of LiAlH4 alloys with dope and undope Ni/C catalysts and characterization and testing of hydrogen adsorption/desorption capacities using these alloys have been carried out. The alloy was made by the milling method and the resulting alloy was characterized using XRD analysis. The adsorption capacity test of the alloy was carried out by the gravimetric method at various pressures. The adsorption capacity of the LiAlH4 alloy by adding additives in the form of Ni/C as much as 5%w/w was proven to increase the hydrogen adsorption capacity compared to undope a catalyst with the highest storage capacity at a pressure of 3 bar of 13.06%w/w compared to undope a catalyst of 9.84%w/w at the same pressure. Meanwhile, the highest hydrogen desorption capacity was 53.56% w/w (dope catalyst) and 41.75% w/w (undope catalyst).
Optimization of Bio-Oil Pyrolysis Product from Palm Empty Fruit Bunches over H-Zeolite Catalyst using Response Surface Methodology (RSM)
Zainal Fanani;
Addy Rachmat;
Hasanudin hasanudin;
Muhammad Said
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 6, No 3 (2021): October 2021
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v6.i3.122
Bio-oil pyrolysis product considered as a promising resource of hydrocarbon compound that can be used as alternative fuel or other application. Palm empty fruit bunch (PEFB) based bio-oil converted into hydrocarbon trough pyrolysis over sulfate activation natural zeolite. Here, we reported an optimization process of bio-oil pyrolysis specifically on temperature and catalyst dose variables by using response surface methodology (RSM). Prior conversion process, PEFB was analyzed to determine cellulose, hemicellulose and lignin content. Sulfate activation natural zeolite confirmed its acidity by ammonia and pyridine adsorption calculated by gravimetric method. Two independent variables namely temperature and catalyst weight used in optimization process by RSM whereas response variable is conversion percentage. Analysis result on cellulose, hemicellulose and lignin content are 45.39%, 30.36% and 20.5% respectively. Catalyst acidity determination based on ammonia and pyridine adsorption gave 1.002 mmol/g and 0.1994 mmol/g. Optimum condition of hydrocracking achieved at 568 °C and 2.1088 g catalyst weight with the product obtained at 62.21% conversion. The best product density is 1.086 g/mL obtained at hydrocracking temperature 554 °C and 2.0362 g catalyst. Based on GC-MS analysis, it was confirmed that the product comprises more straight-chain hydrocarbon than cyclic one. RSM calculation able to formulate the feasible model equation to predict the conversion percentage. The equation is; percent conversion = 60.059 + 14.268T + 9.783W – 25.649T2 – 18.809W2 + 3.114TW, whereas model equation for response variable on product density; ρ= 1.09103 – 0.12356T – 0.09744W + 0.11489T2 + 0.28888W2 – 0.00740TW
Production of Biodiesel from Esterification of Oil Recovered from Palm Oil Mill Effluent (POME) Sludge using Tungstated-Zirconia Composite Catalyst
Hasanudin Hasanudin;
Addy Rachmat
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 1, No 2 (2016): June 2016
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
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DOI: 10.24845/ijfac.v1.i2.42
Solid acid catalyst prepared from tungsten and zirconium oxide composite had been characterized and evaluated on biodiesel production by esterification of low quality oils taken from POME sludge. Catalyst characterization was conducted using Scanning Electron Microscopy (SEM) and acidity test. Acidity test of catalyst resulted using Gravimetry method is 5.4 mole/g. Esterification to produce biodiesel using tungsten and zirconium oxide composite show increasing amount of catalyst used will also increased conversion percentage of biodiesel produced and reach optimum value at 10%. Catalyst:oil ratio used to produce optimum conversion is 8:1 which converted 74.88% oil to biodiesel.Keywords: Tungsten-Zirconia composite, POME Sludge, EsterificationAbstrak (Indonesian). Penelitian tentang preparasi dan karakterisasi katalis komposit tungsten dan zirkonium oksida serta aplikasinya untuk esterifikasi minyak hasil recovery limbah sludge industri kelapa sawit telah dilakukan. Karakterisasi katalis dilakukan dengan menggunakan SEM dan uji sifat keasaman. Sifat keasaman katalis didapat sebesar 5,4 mol/g dengan metode gravimetri. Hasil pembuatan biodiesel dengan menggunakan katalis komposit tungsten dan zirkonium oksida didapatkan bahwa semakin besar jumlah katalis yang digunakan semakin besar pula % konversi biodiesel yang dihasilkan dan optimum pada 10%. Sementara perbandingan jumlah metanol:minyak didapatkan nilai optimum pada perbandingan 8:1 dengan % konversi biodiesel sebesar 74,88%.Kata Kunci: Tungsten-Zirconia composite, POME Sludge, Esterifikasi
CuAl LDH/Rice Husk Biochar Composite for Enhanced Adsorptive Removal of Cationic Dye from Aqueous Solution
Neza Rahayu Palapa;
Tarmizi Taher;
Bakri Rio Rahayu;
Risfidian Mohadi;
Addy Rachmat;
Aldes Lesbani
Bulletin of Chemical Reaction Engineering & Catalysis 2020: BCREC Volume 15 Issue 2 Year 2020 (August 2020)
Publisher : Department of Chemical Engineering - Diponegoro University
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DOI: 10.9767/bcrec.15.2.7828.525-537
The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with the biochar that evidenced by the broadening of XRD peak at 2θ = 24° and the appearance of a new peak at 1095 cm−1 on the FTIR spectra. The BET surface area analysis revealed that CuAl/BC composite exhibited a larger surface area (200.9 m2/g) that the original CuAl LDH (46.2 m2/g). Surface morphological changes also confirmed by SEM image, which showed more aggregated particles. The result of the adsorption study indicated the composite material was efficient in removing malachite green with Langmuir maximum adsorption capacity of CuAl/BC reaching 470.96 mg/g, which is higher than the original CuAl LDH 59.523 mg/g. The thermodynamic analysis suggested that the adsorption of malachite green occurs spontaneously (ΔG < 0 at all tested temperature) and endothermic nature. Moreover, the CuAl/BC composite showed strong potential as a low-cost adsorbent for cationic dye removal since it showed not only a high adsorption capacity but also good reusability. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).