Akhmad Syoufian's research while affiliated with Universitas Gadjah Mada and other places

Publications (44)

Article
This paper deals with doping TiO2 with sulfur powder by sol–gel method, in order to extend the photocatalytic activity under visible light exposure. Weigh of the sulfur powder was varied as 5, 10, and 20 mg doped into 12.5 mmoles of TTIP, (theoretically the same as 100 mg of TiO2) to get 5%, 10%, and 20% of S contained in the prepared TiO2–S. The S...
Article
Hydrocracking of low-density polyethylene (LDPE) plastic over an impregnated Ni catalyst on activated natural zeolite (Ni/ANZ) has been carefully investigated. Natural zeolite was firstly activated with HCl 6 M under reflux conditions followed by wet-impregnation with Ni salts. The obtained powder was calcined at 500 °C followed by a reduction with...
Article
Iron (Fe) and nitrogen (N) were introduced as dopants into zirconium titanate (ZrTiO4) in order to study the codoping effects of nitrogen on iron-doped zirconium titanate (Fe,N-codoped ZrTiO4) composite. Titanium tetraisopropoxide (TTIP), zirconia (ZrO2), urea, and iron(II) sulfate heptahydrate were used as the source of TiO2, semiconductor support...
Article
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Acid and base catalysts have been successfully synthesized, characterized, and applied. This research aimed to synthesize catalysts for biodiesel conversion from waste cooking oil. Acid catalyst (SO4/SiO2) was used to reduce the free fatty acid (FFA) from feedstock and base catalyst (KF/SiO2) was used to convert the oil into biodiesel. The catalyst...
Article
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The highest activity and selectivity results were achieved in the presence of Mo metal supported by SBA-15. Mo/SBA-15 catalyst was synthesized using the wet impregnation method. Catalysts were characterized using FTIR, XRD, Surface Area Analyzer (SAA), and SEM-EDX. Mo/SBA-15 has pore diameters, surface area, and Mo metal concentration of 561.4 m²/g...
Article
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In this study, natural source Parangtritis beach sand was extracted into mesoporous silica (MS). Synthesis of mesoporous silica (MS) was carried out at sodium silicate: CTAB ratio of 1:0.5 (w/w). Monometallic catalyst was used to improve the performance of the catalyst. The monometallic used was Mo metal, which was synthesized using the wet impregn...
Article
Biodiesel is a renewable energy source that can be produced through esterification as well as transesterification reactions. This work presents a series of zirconia catalysts synthesized by hydrothermal method on various concentrations in acidic (H2SO4 0.3, 0.5, and 0.7 M) and basic (NaOH 1, 2, 3, and 4 M) solution to get a catalyst with the highes...
Article
Full-text available
In this work, the optimum condition for hydrocracking waste palm oil (WPO) over Mo/SiO2 catalyst was studied in order to obtain biofuel with high level hydrocarbon. Natural source Parangtritis beach sand was utilized to provide amorphous silica support for preparing Mo/SiO2 hydrocracking catalyst via wet impregnation in five different Mo concentrat...
Article
The synthesis of the nickel-loaded sulfated zirconia catalyst (Ni-SZ) and its application for the hydrocracking process have been carried out. This work has been conducted to determine the activity and selectivity from various Ni concentrations loaded on sulfated zirconia (SZ) in the hydrocracking of used palm cooking oil. The synthesis technique w...
Article
The present study reports the effective combination of zirconia superacid and zirconia-impregnated CaO in biodiesel manufacturing through the utilization of used coconut cooking oil. The acid catalyst was synthesized by the wet impregnation method combined with H2SO4 0.9 M. This mixture was calcined at 500 °C and yielding the highest catalyst acidi...
Article
The synthesis of the Ni-Mo sulfated zirconia (NiMo-SZ) catalyst and its application to convert waste cooking oil into biofuel was successfully conducted. The synthesis process was started with a sulfation process on the zirconia oxide (ZrO 2 ) using 0.5, 1.0, and 1.5 M sulfuric acid (H 2 SO 4 ) through wet impregnation to obtain sulfated zirconia (...
Article
Full-text available
The Co, Ni, and Zn metal catalysts impregnated on mesoporous carbon from Merbau wood sawdust have been prepared and aimed to improve the hydrocracking activity of cellulose bio-oil into a functional liquid product. Carbon-based sawdust as catalyst support was carbonized at various temperatures which subsequently denoted as C500, C600, C700, and C80...
Article
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The effects of dopant content and calcination temperature on Mn-doped TiO2-ZrO2 structure and properties were successfully investigated. Composite of Mn-doped titania-zirconia was synthesized by sol-gel method. Titanium(IV) isopropoxide was used as the precursor of TiO2, while zirconiapowder was used as another semiconductor. MnCl2∙4H2O was used as...
Article
Full-text available
Silica-based solid acid catalysts have been successfully prepared and characterized. This research aimed to study the effect of sulfuric acid and calcination temperature on the properties of silica-based solid acid catalyst chemically and physically. The catalyst was synthesized with tetraethyl ortho silicate (TEOS) as precursor of SiO2 through the...
Article
A novel, highly active and effective adsorbent has been developed using solid state mixing method of natural bentonite and CaO. The so called CaO/bentonite nanocomposite was determined the optimum heating temperature and bentonite-to-CaO ratio to enhance the quality of patchouli oil by purification process technology. The adsorbents were characteri...
Preprint
Full-text available
In this study, natural source Parangtritis beach sand was extracted into mesoporous silica (MS). Synthesis of mesoporous silica (MS) was carried out at sodium silicate: CTAB ratio of 1:0.5 (w/w). Monometallic catalyst was used to improve the performance of the catalyst. The monometallic used was Mo metal, which was synthesized using the wet impregn...
Article
Transesterification reaction of castor oil catalyzed by Na2O/ZrO2 to produce biodiesel has been investigated. The catalyst was made by activating the ZrO2 with 98\% NaOH 5 M, dried in oven for 24 hours, and followed by calcination in a muffle furnace at 500 oC for 5 hours. XRD analysis shows that the catalyst has typical peaks at 2? = 38.32o, 33.19...
Article
Bentonite was modified through intercalation and calcination using a ZrOCl 2 pillaring solution. To create nano Ni/ZrO 2 -bentonite catalyst, ZrO 2 pillared bentonite was impregnated using Ni(NO 3 ) 2 •6H 2 O precursor first, then followed by calcination and reduction. The physical-chemical properties of the catalyst was characterized by XRD (X-ray...
Article
Full-text available
The synthesis of diethanolamide surfactant from used cooking oil was systematically studied using modified zeolite as catalyst. The activated zeolite was obtained by dispersing natural zeolite in sulfuric acid (H2SO4) solution. Potassium carbonate (K2CO3) was loaded into activated zeolite by wet impregnation method. The methyl ester obtained from t...
Article
Full-text available
Synthesis of cobalt-doped zirconium titanate (Co-doped ZrTiO4) as a potential photocatalyst with visible-light-response had been conducted. Materials used in this research were titanium tetraisopropoxide (TTIP) as a precursor of TiO2, ZrO2 as another semiconductor for coupling, and CoSO4·7H2O as the source of cobalt dopant. The composite was prepar...
Article
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The synthesis of CaO/zeolite nanocomposite as a highly active and effective adsorbent for patchouli oil purification has been developed. This research aims to improve the quality of patchouli oil by synthesizing CaO/zeolite nanocomposites using a solid-state mixing method. The used mass ratios of zeolite:CaO were 0:100, 20:80, 40:60, 60:40, 80:20 a...
Article
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The preparation and characterization of zirconia-supported titania with a zinc dopant had been studied. Zinc-doped titania was grown on the surface of zirconia by the sol-gel method. Various zinc contents and calcination temperatures were applied to investigate the zinc doping effect and crystal structure of the zirconia-titania composite. X-ray di...
Article
Full-text available
The preparation, characterization, and catalytic activity test of sulfated zirconia (SZ) modified with chromium for the hydrocracking of LDPE-based plastic waste have been investigated. SZ was prepared by wet impregnation method using zirconia nanopowder (ZrO2) and H2SO4 solution. SZ was further modified with chromium (0.5, 1.0, and 1.5% wt.%) by r...
Article
Full-text available
It has been carried out preparation of Chrom/Nanocomposite ZrO 2 -Pillared Bentonite catalyst with varying the amount of impregnating precursor at 0 to 3% (w/w). Material characterization of catalyst was carried out using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Infrared Spectroscopy (IR), Transmission Electron Microscope (TEM), Brunauer,...
Article
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Synthesis and characterization of Cu-doped zirconium titanateas a potential visible-light responsive photocatalyst had been conducted. Titanium tetraisopropoxide (TTIP) was used as a precursor of Ti source, reacted to ZrO2 powderand CuSO4·5H2O with various Cu concentrations of 0, 1, 3, 5, 7 and 9% (w/w) by sol-gel method. Zirconium titanate with Cu...
Article
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Synthesis and properties of iron-doped zirconium titanate (ZrTiO4) as a potential visible-light-responsive photocatalyst had been conducted. Various iron dopant concentration and calcination temperature were investigated toward the properties of Fe-doped ZrTiO4. The photocatalyst material was synthesized by sol-gel and impregnation method. Titanium...
Article
Full-text available
Hydrocracking of LDPE plastic waste into liquid fuel was conducted by using sulfated zirconia (SZ) and Cr metal supported on SZ (Cr/SZ) catalysts. Catalysts were prepared and characterized by SEM-EDS, SAA, and TGA-DTA. The liquid produced was characterized by GC-MS. The characterization result showed the sulfate group was successfully impregnated o...
Article
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Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2...
Article
This research aims to determine characteristics of the magnetic properties of Fe3O4-(CTAB-Montmorillonite) composites and the effect of variation in Fe³⁺/Fe²⁺ concentrations on the characteristics of Fe3O4-(CTAB-Montmorillonite) composites. Fe3O4-(CTAB-Montmorillonite) composites were synthesized using an in situ co-precipitation method. The synthe...
Article
Synthesis and characterization of Cr/Al2O3-bentonite nanocomposite as a hydrocracking catalyst of castor oil have been conducted. The catalyst was prepared according to the following method. At the first step, bentonite was activated using H2SO4 to obtain H-bentonite, after that the activated clay was pillarized by Al2O3, Next, a salt solution of C...
Article
The research was focused on the modification of natural montmorillonite by using cationic surfactant cetyl trimethylammonium bromide (CTAB). The natural bentonite was washed with distilled water to clean the impurites of nature bentonite in order to get the montmorillonite fraction. A variation of the amount of CTAB, which is used for the preparati...
Article
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The Fe3O4/SiO2/TiO2 nanocomposite has been prepared by coating magnetite core particles with silica and photoactive titania using sonocoprecipitation and sol-gel methods followed by microwave assisted synthesis. The nanocomposite was characterized by X-ray diffraction, infrared spectroscopic analysis, diffuse reflectance spectroscopy and transmissi...
Article
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Preparation, characterization and catalytic activity testing of chrome-bentonite for hydrocracking reaction of used cooking oil into biofuel have been done. Chrome-bentonite preparation began by reacting Na-bentonite with 1 M H2SO4 to obtain sample of the H-bentonite. Chrome-bentonite catalyst preparation was performed through impregnation method o...
Article
Photoactive srilankite-type zirconium titanate hollow spheres with submicrometer size have been successfully synthesized by employing sulfonated polystyrene (PS) latex particles as a template in conjunction with the sol–gel method. The structure of the particles was characterized by scanning electron microscopy and transmission electron microscopy....
Article
Full-text available
Methane has been used as a source of renewable fuels that are environmentally friendly. ZSM-5 catalyst is used for the conversion of methane into gasoline. These materials are generally synthesized using an organic template that is likely to cause environmental problems. Mesoporous ZSM-5 was synthesized successfully from Sidoarjo mud as silica sour...
Article
The study on the preparation and preparation of activated carbon from coconut shell charcoal via the combined chemical (ZnCl2) and physical (CO2) activations has been carried out. This study was aimed to study the chemical change occurred during the activation. The charcoal was immersed in the solution of ZnCl2, where the concentration of solution...
Article
Hydrocracking of used cooking oil catalyzed by Ni-bentonite has been conducted. Synthesis of Ni-bentonite was begun with the activation of bentonite by refluxing the bentonite using 6 M HCl followed by 1 % Ni metal impregnation derived from precursor NiCl2·6H2O. Ni-bentonite was analyzed by FT-IR, XRD and gas sorption analyzer. Its acidity value wa...
Article
The preparation, characterization and catalytic activity test of Cr/acid activated natural zeolite on palm oil hydrocracking reaction into liquid biofuels fraction were performed. Natural zeolite obtained from Klaten, Indonesia was activated with 1 M sulfuric acid to obtain a sample of acid activated natural zeolite (ZZA). The catalysts preparation...
Article
Submicrometer-sized titania hollow spheres have been synthesized by employing sulfonated polystyrene latex particles (averaged diameter: 200 nm) as a template in conjunction with the sol-gel method. Utilization of 0.20 mol/L titanium tetrabutoxide and 25 g/L latex led to the formation of anatase particles having shell thickness of about 15 nm and v...
Article
The submicrometer-sized titania hollow spheres have been synthesized by employing sulfonated polystyrene latex particles as a template in sol-gel method. Photocatalytic activity of the hollow spheres was investigated by focusing on the effect of electron scavengers in the photocatalytic decomposition of methylene blue (MB). Photocatalytic activitie...
Article
The submicrometers-sized titania hollow spheres have been synthesized by employing sulfonated-polystyrene latex particles as a template in sol–gel method. The hollow spheres have relatively smooth surface and dense arrangement of titanium dioxide layers. Photocatalytic activity of the hollow spheres was investigated by employing methylene blue (MB)...
Article
Submicrometer-sized titania hollow spheres with tunable shell thickness and smooth surfaces have been successfully synthesized by employing sulfonated polystyrene (PS) latex particles as a template in sol–gel method. The structure of the particles was characterized by scanning electron microscopy and transmission electron microscopy. The shell thic...

Citations

... Most of the catalysts used in the hydrocracking process are bifunctional catalysts, as they comprise metal as hydrogen-dehydrogenation process and support. The metal function is provided by noble metals such as Pt [20,21] and Pd [21] and transition metal such as Ni [22], while the support was provided by nonacidic support such as SiO 2 [23] and SBA-15 [24] and acidic support such as SAPO-11 [21] and zeolite [26]. In the presence of Ni-based catalyst, ricinoleic acid in castor oil turned into gasoline fuel and jet fuel [22]. ...
... Ore et al. [15] reported that the number of Brønsted and Lewis acid sites depends on the SO4 2− concentration present on the catalyst surface. Sulfation with optimum sulfate concentration can increase the catalytic activity of the catalyst, while the decrease in catalyst acidity with increasing temperature occurs due to dehydration of protonic sites and loss of SO4 2− groups on the surface of the catalyst [38][39][40]. Qualitatively, the number of Brønsted and Lewis acid sites can be observed absorption spectra intensity that denotes the interaction between the catalyst acid sites and NH3 [41]. Figure 5 presents the FTIR spectra of the catalyst after the acidity test. The absorption peak at 1119-1126 cm −1 indicates the presence of NH3 coordinated to the Lewis acid site. ...
... Sulfate and Cr impregnation on ZrO2 have a lower intensity peak than ZrO2. This is due to the presence of sulfate on ZrO2 and to Cr metal covering the surface of SZ, inhibiting the growth of ZrO2 crystals and thereby decreasing the crystallinity of the materials [73,74]. ...
... Ore et al. [15] reported that the number of Brønsted and Lewis acid sites depends on the SO4 2− concentration present on the catalyst surface. Sulfation with optimum sulfate concentration can increase the catalytic activity of the catalyst, while the decrease in catalyst acidity with increasing temperature occurs due to dehydration of protonic sites and loss of SO4 2− groups on the surface of the catalyst [38][39][40]. Qualitatively, the number of Brønsted and Lewis acid sites can be observed absorption spectra intensity that denotes the interaction between the catalyst acid sites and NH3 [41]. Figure 5 presents the FTIR spectra of the catalyst after the acidity test. The absorption peak at 1119-1126 cm −1 indicates the presence of NH3 coordinated to the Lewis acid site. ...
... This research utilizes Ni metal as the catalyst material and Parangtritis beach sand as the carrier. Numerous studies on catalysts derived from beach sand have been conducted because of the silica-rich nature of beach sand [6,7] for hydrocracking of used palm oil into hydrocarbon compounds. The liquid product and total hydrocarbon compounds obtained were 69.75 and 94.33 wt%, respectively. ...
... Figure 4 shows the same absorption peak at wave number 424-741 cm −1 , indicating the Zr-O-Zr bond [32]. Absorptions at 3426-3449 and 1636 cm −1 refer to the O-H stretching and bending vibrations of the water molecules adsorbed on the material [33]. In addition, according to Ore et al. [15], the broadband in the absorption region of 3400 cm −1 signifies the bridge between the hydroxyl group with two or three Zr atoms. ...
... Modification of SiO2 can involve the sulfation process using a sulfate solution, H2SO4. The addition of sulfuric acid in the process can increase the acid strength and, thus, the reactivity of SiO2 [4]. In addition, SO4 will be present on the catalyst surface from the sulfation process, providing Lewis and Bronsted acid sites that play a role in increasing chemical products [5,6]. ...
... This may be attributed to the depletion of water molecules bound in zeolite structures because of the calcination and oxidation reactions . The release of water molecules (free -OH group) is also approved due to the higher transmittance in the wavenumber range of 1600-1450 cm -1 for acid-washed zeolites (Wijaya et al., 2020). Moreover, due to calcination, oxidation, and thermal effect, some functional groups were released from their bonds (Zhou et Zeolites containing clinoptilolite and mordenite types are reported to have strong stretching vibrations in the wavenumber range of ~1045-1070 cm -1 for the Si-O-Al and Si-O-Si groups. ...
... Therefore, it cannot be unambiguously stated how the pH of the environment affects the efficiency of photodegradation of tetracycline. In previous studies it was proven that combination of ZrO 2 and TiO 2 (ZrO 2 -TiO 2 , ZrTiO 4 ) may have beneficial effect on the photocatalytic performance through production of composite with higher photocatalytic activity compared to pure TiO 2 , smaller bandgap than pure ZrO 2 , and good thermal stability (Sulaikhah et al., 2020). UV irradiation of TiO 2 -ZrO 2 /La photocatalyst causes the extraction of the electron from the valence band to the conduction band, leaving an equal number of vacant sites (holes) (Eq. ...
... However, the highest metal concentration could reduce the liquid yield. This is in agreement with the previous finding by Hauli et al. [41], where the decrease amount of liquid yield correlated to the acidity of catalyst. The Ni 3 Mo 3 / HS3 has the smallest total acidity compared to other NiMo catalysts. ...