scholarly journals The Effect of Using H4P2O7 as Phosphorus Source for Synthesizing Vanadyl Pyrophosphate Catalysts

2017 ◽  
Vol 6 (3) ◽  
pp. 207
Author(s):  
Y.H. Taufiq-Yap ◽  
A. Raslan ◽  
R. Irmawati
Keyword(s):  
Surface Area ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Vanadyl Pyrophosphate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Area Measurement ◽  
Phosphorus Source ◽  
Temperature Programmed ◽  
Two Peaks

<p>Vanadyl pyrophosphate (VO)<sub>2</sub>P<sub>2</sub>O<sub>7</sub> catalysts synthesized via VOPO<sub>4</sub>·2H<sub>2</sub>O were investigated by using BET surface area measurement, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Temperature-Programmed Techniques (TPD and TPRS). H<sub>3</sub>PO<sub>4</sub> and H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> were used as the phosphorus source. Only pyrophosphate phase was observed for both final catalysts after 75 hours of calcination in a reaction flow of <em>n</em>-butane/air mixture (0.75% <em>n</em>-butane/air). However, catalyst derived from H<sub>4</sub>P<sub>2</sub>O<sub>7</sub> based preparation (denoted VPD<sub>pyro</sub>) exhibit better crystallinity and slightly higher BET surface area compared to the H<sub>3</sub>PO<sub>4</sub> based preparation (denoted VPD<sub>ortho</sub>). The nature of the oxidants for both catalysts was investigated by O<sub>2</sub>-TPD. For VPD<sub>pyro</sub>, TPD showed an oxygen peak maximum at 986 K and a shoulder at 1003 K, whereas for VPD<sub>ortho</sub>, the oxygen was desorbed as two peaks maxima at 966 and 994 K. The total amount of oxygen desorbed thermally from VPD<sub>pyro</sub> (3.60×10<sup>20</sup> atom×g<sup>-1</sup>) is higher than that obtained for VPD<sub>ortho</sub> (3.07×10<sup>20</sup> atom×g<sup>-1</sup>). VPD<sub>pyro</sub> displayed a slightly improved activity and selectivity for <em>n</em>-butane oxidation. A proper amount of V<sup>5+</sup> species may have an effect on the enhancement of the catalytic activity.</p>

Preparation and Characterization of Flowerlike Nickel Oxide

2011 ◽  
Vol 121-126 ◽  
pp. 1044-1048
Author(s):  
Chang Yu Li ◽  
Shou Xin Liu ◽  
Li Li Liu
Keyword(s):  
Nickel Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Area Measurement ◽  
Simple Liquid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Area Measurement

Flowerlike nickel oxide was synthesized by a simple liquid-phase process to obtain the hydroxide precursor and then calcined to form the nickel oxide. The precursor and the nickel oxide were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) , the scanning electron microscope(SEM) and Brunauer–Emmett–Teller-specific surface area measurement. The results indicated α-Nickel hydroxide was transferred to NiO with a cubic crystalline structure after being calcined at 450 °C; the NiO still kept the morphology of the precursors and the specific surface area of the NiO was 125.2m2/g.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

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.

Effects of the Pre-Freezing Time on the Structures and Electrochemical Performances of Co-B Alloys

2011 ◽  
Vol 391-392 ◽  
pp. 1085-1089 ◽  
Author(s):  
Chuan Wu ◽  
Chun Hui Pang ◽  
Feng Wu ◽  
Ying Bai ◽  
Chi Chen ◽  
...  
Keyword(s):  
Cycling Performance ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Electrochemical Performances ◽  
Freezing Time ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Surface Area Measurement ◽  
A Current ◽  
Discharge Test

A series of Co-B alloys with uniform nanoparticles were prepared via a vacuum freeze-drying method, which the precursors of Co-B alloys were prepared by the reduction of bivalent cobalt chloride with aqueous sodium borohydride solution. The alloys were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and brunauer emmett teller (BET) surface area measurement. The electrochemical activities of Co-B samples were examined by charge-discharge test. This work studied the influence of pre-freezing time on the microstructure and electrochemical performance. The sample pre-freezing for 3 hours exhibits the best cycling performance than others, the discharge capacity increase to its maximum 438mAh/g, and it still remained 232 mAh/g after 60 cycles at a current of 50 mAh/g; while those of samples pre-freezing for 1 hour and 5 hours are 399 mAh/g and 413mAh/g, respectively.

Vacuum Carburization of Nanometer Tungsten Powder with Carbon Black

2007 ◽  
Vol 534-536 ◽  
pp. 165-168 ◽  
Author(s):  
Luo Ji ◽  
Lin Tao ◽  
Zhi Meng Guo ◽  
Cheng Chang Jia
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Surface Area ◽  
Tungsten Powder ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Vacuum Carburization ◽  
Dta Curves

Vacuum carburization of nanometer tungsten powder was investigated in a simple designed apparatus. An X-Y recorder was used to plot differential thermal analysis (DTA) curves to determine the starting temperature of carburization of four samples with different specific surface area. The product was characterized by X-ray Diffraction (XRD) and small angle X-ray scattering (SAXS). The results show that finer tungsten powder has lower starting temperature of carburization. Tungsten powder, the BET surface area of which is 32.97m2/g, was completely carburized to tungsten carbide at 1050°C, even though the starting temperature was 890°C. The particle was found to grow sharply before carburization.

Characterization of Nanosilica of Tapioca Peel as Adsorbent for Biomethane Storage System

2015 ◽  
Vol 1125 ◽  
pp. 266-270
Author(s):  
Hasnizah binti Habibun ◽  
Shareena Fairuz binti Abdul Manaf ◽  
Nur Hashimah Alias ◽  
Nur Shahidah Ab Aziz ◽  
Fazlena Hamzah
Keyword(s):  
Physical Properties ◽  
Metal Oxides ◽  
Surface Area ◽  
Storage System ◽  
Physical Structure ◽  
Area Measurement ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Adsorption And Desorption ◽  
Adsorption And Desorption Performance

Biomethane is an alternative and renewable source that occurred naturally which produced from the anaerobic digestion of organic matter. It can be used as the electricity power generation, water heating and also vehicle fuel. In this study, the characteristics of the nanosilica of the tapioca peel as an adsorbent on the structural and physical properties to store the biomethane were investigated. To enhance the adsorption and desorption performance as well as the structural and physical properties, the nanosilica was modified with the metal oxides. The metal oxides that have been used to modify the nanosilica adsorbent are zinc (II) oxide (ZnO) and nickel (II) oxide (NiO). Both of the modified and unmodified nanosilica structural properties were characterized by using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). While, the physical properties of both of the modified and unmodified nanosilica were characterized by using Brunauer, Emmet, Teller (BET) surface area measurement. The effects of both types of metal oxides with different concentration were investigated. Based on the results obtained, the structural and physical characteristics of the nanosilica were affected by the different metal oxides loading. It have been identified that 1% ZnO modified nanosilica has highest BET surface area (8.32 m2/g) with pore volume (19.23 cc/g) and pore size (82.8 nm). Thus, it concluded that 1% ZnO modified nanosilica improved the structural and physical structure. Hence, it enhances the capacity of methane adsorption and desorption prior to storage system.

scholarly journals Synthesis and Characterisation of Mesoporous TiO2 Nanoparticles by Novel Surfactant Assisted Sol-gel Method for the Degradation of Organic Compounds

2018 ◽  
Vol 63 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Harish Phattepur ◽  
Gowrishankar Bychapur Siddaiah ◽  
Nagaraju Ganganagappa
Keyword(s):  
Electron Microscopy ◽  
Tio2 Nanoparticles ◽  
Surface Area ◽  
Sol Gel ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Tio2 Nps ◽  
Gel Method ◽  
X Ray ◽  
Surfactant Assisted

A sol-gel method was employed to synthesise pure titanium dioxide (TiO2) and surfactant assisted TiO2 nanoparticles (NPs). The effect of novel surfactant viz., Lauryl lactyl lactate on photocatalytic properties of TiO2 was studied. TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Diffuse Reflectance spectra (DRS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Thermo gravimetric analysis (TGA), and Brunauer – Emmet - Teller (BET) surface area. Anatase phase of TiO2 was confirmed by X-Ray diffraction pattern and the crystallite size was between 9–19 nm. Addition of surfactant improved the BET surface area, surface defects, while the agglomeration of particles was reduced. DRS results revealed that the addition of surfactant to TiO2 sol induced a red shift of the absorption edge which resulted in the reduction of band gap from 3.23 to 3.21 eV. These physicochemical properties of TiO2 NPs were correlated with photocatalytic degradation of phenol. About 92% of phenol degradation was observed for surfactant assisted TiO2 NPs (SA-TiO2). Salicylic acid and caffeine were also degraded using SA-TiO2 NPs.

Synthesis of Nano-Barium Titanate and Application for Strontium Adsorption from Aqueous Solution

2016 ◽  
Vol 1141 ◽  
pp. 190-195
Author(s):  
Hitesh Saravaia ◽  
Hariom Gupta ◽  
Vaibhav Kulshreshtha
Keyword(s):  
Barium Titanate ◽  
Surface Area ◽  
Active Surface ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Ft Ir ◽  
Tetragonal Batio ◽  
Thermal Stability Of

Barium Titanate (BaTiO3) nanostructures are synthesized by the molten salt-hydroxide reaction. The crystalline phase and chemical structure of the synthesized material are analyzed using powder x-ray diffraction (XRD) and FT-IR techniques, revealing the tetragonal BaTiO3 crystalline structure. Morphology and thermal stability of the material are characterized using TEM and TG-DTG analysis. BET surface area analysis shows significant active surface available for adsorption and its surface area value is found to be 14.8427 m2 g-1. The maximum adsorption of strontium metal is found to be 56.3 for the 1.2 g L-1 BaTiO3 adsorbent dose which reveals a remarkable separation property of the BaTiO3.

Sign in / Sign up

Export Citation Format

Share Document