scholarly journals Oxidation of 3- and 4-Methylpyridines on Vanadium-Anatase and Vanadium-Rutile Catalysts

2012 ◽  
Vol 14 (4) ◽  
pp. 337
Author(s):  
O.K. Yugay ◽  
T.P. Mikhailovskaya ◽  
D.Kh. Sembaev ◽  
P.B. Vorobyev
Keyword(s):  
Surface Area ◽  
Isonicotinic Acid ◽  
Thermal Dissociation ◽  
Dissociation Rate ◽  
Bet Surface Area ◽  
Titanium Catalysts ◽  
Heterogeneous Catalytic ◽  
Vanadium Titanium ◽  
Crystal Modifications

<p>Heterogeneous catalytic vapor-phase oxidation of methylpyridines is “green”, the most simple and perspective method for obtaining pyridinecarboxylic acids. Vanadium-titanium catalysts have a wide application in some important industrial processes of oxidation. Oxidation of 3-and 4-methylpyridine on vanadium-titanium catalysts has been investigated and for its preparation various titanium crystal modifications were used. Characterization of the catalysts was carried out by using the X-ray diffraction, N<sub>2</sub>-adsorbtion and thermal dissociation of V<sub>2</sub>O<sub>5</sub>. It was found that the use of anatase type of TiO<sub>2</sub> with a higher BET surface area enhances the activity of the vanadium-titanium catalyst extremely. XRD-characterization of catalysts demonstrated that the only V<sub>2</sub>O<sub>5</sub> and anatase or V<sub>2</sub>O<sub>5</sub> and rutile phase was detected. It was established that the use of titanium dioxide of crystal modifications of anatase increases on the order of the dissociation rate V<sub>2</sub>O<sub>5</sub>. It was shown that vanadium-titanium catalysts’ activity and selectivity in investigated processes depends on TiO<sub>2</sub> crystal modifications.V<sub>2</sub>O<sub>5</sub>-anatase is more active and selective in formation of pyridine carboxylic acids. V<sub>2</sub>O<sub>5</sub>-rutile in the process of oxidation of 4-methylpyridine on the catalyst forms the mixture of isonicotinic acid and its aldehyde. Connection between the dissociation rate of V<sub>2</sub>O<sub>5</sub> in catalysts of V<sub>2</sub>O<sub>5</sub>-anatase and V<sub>2</sub>O<sub>5</sub>-rutile and their activity in isomeric methylpyridines oxidation was established. High surface area, anatase structure of titanium are the key parameters determining the activity and selectivity of vanadium-titanium oxidation catalysts.</p>

Synthesis and Characterization of Hematite Nanoparticles as Active Photocatalyst for Water Splitting Application

2013 ◽  
Vol 594-595 ◽  
pp. 73-77 ◽  
Author(s):  
Sze Mei Chin ◽  
Suriati Sufian ◽  
Jeefferie Abd Razak
Keyword(s):  
Surface Area ◽  
Water Splitting ◽  
Combustion Method ◽  
Hydrogen Gas ◽  
Bet Surface Area ◽  
Synthesis And Characterization ◽  
Hematite Nanoparticles ◽  
X Ray ◽  
Bet Specific Surface Area

This paper highlights on the hydrogen production through photocatalytic activity by using hematite nanoparticles synthesized from self-combustion method based on different stirring period. The morphologies and microstructures of the nanostructures were determined using Field-Emission Scanning Electron Microscope (FESEM), X-Ray Diffractometer (XRD) and Particle Size Analyser (PSA). Besides that, surface area analyser was used to determine the BET surface area of the hematite samples. The hematite nanocatalyst as-synthesized are proven to be rhombohedral crystalline hematite (α-Fe2O3) with particle diameters ranging from 60-140 nm. The BET specific surface area of hematite samples increased from 5.437 to 7.6425 m2/g with increasing stirring period from 1 to 4 weeks. This caused the amount of hydrogen gas produced from photocatalytic water splitting to increase as well.

scholarly journals Synthesis and Characterization of Co-Mo/γ-Alumina Catalyst from local Kaolin clay for Hydrodesulfurization of Iraqi Naphtha

2021 ◽  
Vol 11 (1) ◽  
pp. 84-106
Author(s):  
Nada Sadoon Ahmed zeki ◽  
Sattar Jalil Hussein ◽  
Khalifa K. Aoyed ◽  
Saad Kareem Ibrahim ◽  
Ibtissam K. Mehawee
Keyword(s):  
Surface Area ◽  
Sulfur Removal ◽  
Sulfuric Acid Concentration ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mo Catalyst ◽  
Pressure Time ◽  
Al2o3 Catalyst

This work deals with the hydrodesulfurization of three types of naphtha feedstocks; mixednaphtha (WN), heavy naphtha (HN) & light naphtha (LN) with a sulfur content of 1642.1,1334.9 & 709 ppm respectively, obtained from Missan refinery using prepared Co-Mo/γ-Al2O3catalyst. The Iraqi white kaolin was used as a starting material for the preparation of γ-Al2O3support, transferring kaolin to meta-kaolin was studied through calcination at differenttemperatures and durations, kaolin structure was investigated using X-Ray diffractiontechniques.High purity 94.83%. Crystalline γ-Al2O3 with a surface area of 129.91 m2/gm, pore volume0.9002 cm3/g was synthesized by extraction of Iraqi kaolin with H2SO4 at different acid to clayweight ratios, acid concentrations & leaching time. Ethanol was used as precipitating agent; theresultant gel was dried and calcined at 70OC, 10 hrs & 900 OC, 2 hrs respectively.The effects of different parameters on the average crystallinity and extraction % ofsynthesized γ-Al2O3 were studied like; acid: clay ratio, sulfuric acid concentration, leachingtime, leaching temperature & kaolin conversion to metakaolin. Characterization of prepared γ-Al2O3 & Co-Mo catalyst were achieved by X-ray diffraction, FTIR-spectra, texture properties& BET surface area, BJH N2 adsorption porosity, AFM, SEM, crush strength & XRF tests. Co-Mo/ γ-Al2O3 catalyst with final loading 5.702 wt% and 21.45 wt% of Co and Mo oxidesrespectively was prepared by impregnation methods.The activity of prepared Co-Mo/γ-Al2O3 catalyst after moulding to be tested forhydrodesulfurization (HDS) of naphtha feedstock W.N, H.N & L.N was performed using apilot hydrotreating unit at petroleum research & development centre, at different operatingconditions. Effects of temperature, LHSV, pressure, time & pore size distribution were studied,the best percentage of sulfur removal is increased with decreasing LHSV to 2 hr-1 as a generaltrend to be 89.71, 99.72, 99.20 % at 310oC for the whole naphtha, heavy naphtha and lightnaphtha feedstocks respectively, at 34 bar pressure and 200/200 cm3/cm3 H2/HC ratio.

Characterization of Activated Carbon from Sugar Cane Husk

2014 ◽  
Vol 699 ◽  
pp. 1006-1011
Author(s):  
Nurul’ Ain binti Jamion ◽  
Siti Mazleena binti Mohamed
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Sugar Cane ◽  
Single Point ◽  
Gravimetric Method ◽  
Bet Surface Area ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Physico Chemical ◽  
Vacuum Method

Interface adsorption of gases and liquid on a clean solid surface could be due to the physical or chemical adsorption. In this study, the activated carbon was prepared from sugar cane husk (powder and granular form) using phosphoric acid (H3PO4) as activating agent. Sample was activated at 500°C for two hours in the furnace and washed using vacuum method. Besides, surface area of activated carbon was defined using Single Point Brunauer-Emmett-Teller (BET) Nitrogen Gas. The physico-chemical characteristics of the prepared activated carbon were characterized by Fourier-Transformed Infrared Spectroscopy (FTIR), gravimetric method, and Field Emission Scanning Electron Microscopy (FESEM). The adsorption study by surfactants, namely CTAB (cationic) and TX-100 (non-ionic) were investigated. The experimental results showed that a good activated carbon was prepared from sugar cane husk granular (SCH-G) gave the highest BET surface area of 860.18 m2/g and the adsorption capacity of SCH-G activated carbon at 25°C using TX-100 (205.81 mg g-1) was greater compared to the CTAB (108.20 mg g-1). This study has shown that the sugar cane husk was a good activated carbon and has potential to be used as adsorbent for the removal of surfactants from aqueous solutions.

Characterization of natural- and organobentonite by XRD, SEM, FT-IR and thermal analysis techniques and its adsorption behaviour in aqueous solutions

Clay Minerals ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 31-44 ◽  
Author(s):  
G. A. Ikhtiyarova ◽  
A. S. Özcan ◽  
Ö. Gök ◽  
A. Özcan
Keyword(s):  
Surface Area ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Textile Dye ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Thermal Analysis Techniques

AbstractIn this study, natural bentonite was modified with hexadecyltrimethylammonium (HDTMA) bromide to obtain organobentonite (HDTMA-bentonite). Bentonite and HDTMA-bentonite were then characterized using XRD, XRF, SEM, FT-IR, thermogravimetric (TG) analysis, elemental analysis and Brunauer-Emmett-Teller (BET) surface area techniques. The HDTMA+ cation was found to be located on the surface and enters the interlayer spaces of smectite according to the XRD and SEM results. FT-IR spectra indicated the existence of HDTMA functional groups on the bentonite surface. The BET surface area significantly decreased after the modification due to the coverage of the pores of natural bentonite. After the characterization, the adsorption of a textile dye, Reactive Blue 19 (RB19), onto bentonite and HDTMA-bentonite was investigated. The maximum adsorption capacity of HDTMA-bentonite for RB19 was 502 mg g-1 at 20°C. The adsorption process followed a pseudo-second-order kinetic model and it was exothermic and physical in nature.

scholarly journals Characterization of Activated Carbons from Oil-Palm Shell by CO2Activation with No Holding Carbonization Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. G. Herawan ◽  
M. S. Hadi ◽  
Md. R. Ayob ◽  
A. Putra
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Oil Palm ◽  
Pyrolysis Temperature ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Surface Characteristics ◽  
Bet Surface Area ◽  
Preparation Time

Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.

Synthesis and Characterization of Green Porous Carbons with Large Surface Area by Two Step Chemical Activation with KOH

2014 ◽  
Vol 67 (4) ◽  
Author(s):  
Noor Shawal Nasri ◽  
Mohammed Jibril ◽  
Muhammad Abbas Ahmad Zaini ◽  
Rahmat Mohsin ◽  
Hamza Usman Dadum ◽  
...  
Keyword(s):  
Surface Area ◽  
Porous Carbon ◽  
Pore Volume ◽  
Potassium Hydroxide ◽  
Chemical Activation ◽  
Bet Surface Area ◽  
Porous Carbons ◽  
Precursor Material ◽  
Proximate And Ultimate Analysis

Porous carbons were synthesized from coconut shell using chemical activation by potassium hydroxide (KOH). N2 adsorption isotherm analysis for BET surface area and pore volume of the synthesized porous carbon were carried out. The Langmuir surface area, BET surface area and pore volume are 1646 m2/g, 1353 m2/g and 0.6 cm3/g, respectively. From the FTIR analysis, hydroxyls, alkenes, carbonyls and aromatics functional groups were identified. The proximate and ultimate analysis shows high percentage of carbon and less ash content which indicates a good precursor material for porous carbon. The carbonization temperature and time were also varied to observe their effect on the yield of char, with carbonization at 7000C for 2 h having highest yield of 32%.

Preparation and Characterization of Ti0.6Cr0.4OxNy Nano-Sized Powder

2008 ◽  
Vol 368-372 ◽  
pp. 1130-1132
Author(s):  
Hong Zhi Wang ◽  
Qi Zhang ◽  
Yun Xin Gu ◽  
Yao Gang Li ◽  
Mei Fang Zhu
Keyword(s):  
Surface Area ◽  
Electron Probe ◽  
Auger Electron ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Cubic Structure

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.

Synthesis and Characterization of Biochars from Textile Sludge Precursors

2014 ◽  
Vol 695 ◽  
pp. 44-47
Author(s):  
Khairunissa Syairah Ahmad Sohaimi ◽  
Norzita Ngadi ◽  
Nurul Atiqah Najlaa Yac’cob
Keyword(s):  
Surface Area ◽  
Adsorption Process ◽  
Oil Pollution ◽  
Bet Surface Area ◽  
Marine Life ◽  
Pollution Treatment ◽  
Percentage Yield ◽  
Different Temperatures ◽  
Textile Sludge

Oil pollution is considered as one of the major problem to the sea and also public watercourse. Oil pollution give bad effects to many aspects like to marine life, water treatment system and overall aquatic ecosystem. Thus, this study is focusing on the oil pollution treatment by using adsorption process. For that purpose, this study investigated the potential of textile sludge (TS) which considered as abundant sludge as a source of biochars. Biochars (BC) from textile sludge was prepared by carbonization at different temperatures; 105 °C, 200 °C, 400 °C, and 700 °C. The synthesized biochars; BC105, BC200, BC400, BC700 was characterized using FTIR spectroscopy and BET surface area. The results obtained from characterization showed that BC700 showed the highest BET surface area, 161.9945m2/g while, the highest percentage yield of biochar was obtained at temperature 105 °C with 98.20%. From FTIR results, BC700 showed less peaks which indicated less presence of functional groups compared to BC105, BC200 and BC400 due to decomposition of raw textile sludge wastes at high elevated temperature. The characterization results also showed that BCs produced from textile sludge wastes have potential for oil pollution treatment.

Preparation and Characterization of Titanate Nanotubes by Hydrothermal Method

2010 ◽  
Vol 177 ◽  
pp. 82-85
Author(s):  
Zhong Sheng Chen ◽  
Wei Ping Gong ◽  
Teng Fei Chen ◽  
Guo Lin Huang ◽  
Wen Yuan Xu
Keyword(s):  
Surface Area ◽  
Treatment Process ◽  
Hydrothermal Process ◽  
Anatase Tio2 ◽  
Titanate Nanotubes ◽  
Bet Surface Area ◽  
Hydrothermal Conditions ◽  
Bet Specific Surface Area ◽  
Ft Ir

Titanate nanotubes (TNTs) were prepared by treatment of anatase-TiO2 nanoparticles in mild hydrothermal conditions. TNTs were characterized by XRD, TEM, FT-IR and BET specific surface area technique. It was found that nanotubes might be NaxH2-xTi3O7 and were formed during the hydrothermal process, rather than during the treatment process with acid solution. The formation mechanism of TNTs can be explained as 3D→2D→1D. After hydrothermally reacting at 130°C for 48h, the as-prepared products exhibit hollow nanotubes with open ends, more than 100 nm in length, 10 nm in outer diameters, large BET surface area and pore volume, which may lead to potential photocatalysis and absorption application.

scholarly journals Synthesis and Characterization of TiO2-CaO and TiO2-CaO-Fe2O3 Photocatalyst for Removal of Catechol

Molekul ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 140
Author(s):  
Candra Yulius Tahya ◽  
Wahyu Irawati ◽  
Karnelasatri Karnelasatri ◽  
Friska Juliana Purba
Keyword(s):  
Surface Area ◽  
Adsorption Property ◽  
Average Pore Size ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Sem Images ◽  
Average Pore ◽  
Xrd Pattern ◽  
Two Peaks

TiO2-CaO and TiO2-CaO-Fe2O3 photocatalysts have been synthesized through the surfactant-assisted sol-gel method. The catalysts were characterized using XRD, FTIR, SEM-ED Sand BET surface area. XRD pattern showed the formation of anatase TiO2 crystal phase both in TiO2-CaO and TiO2-CaO-Fe2O3. The TiO2-CaO has higher crystallinity than TiO2-CaO-Fe2O3. Based on the peak refinement using Rietveld, there are two peaks identified as Fe2O3 hematite in the sample TiO2-CaO-Fe2O3.  BET surface area analysis showed that the average pore size of TiO2-CaO and TiO2-CaO-Fe2O3 catalysts are 8.04 and 8.41 nm respectively, indicating both catalysts are mesoporous.FTIR spectra show that the vibration of Ti-O, Ca-O, and Ca-TiO2 were observed in both catalysts. SEM images confirm that both catalysts are porous material. The catechol removal using TiO2-CaO and TiO2-CaO-Fe2O3 improved with the increase of catalyst concentration. After 360 minutes of UV radiation, the removal of catechol using TiO2-CaO-Fe2O3 reached 46.0%, 48.3%, and 69.2%, while when using TiO2-CaO, it reached 22.1%, 36.8%, and 57.0% for 0.1 g, 0.15 g, and 0.2 g of catalysts, respectively. The photocatalytic activity of TiO2-CaO-Fe2O3 is not so strong compared to TiO2-CaO catalyst but the catechol adsorption property of TiO2-CaO-Fe2O3 is higher than that of TiO2-CaO catalyst.

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