scholarly journals Characterization of Mn-Doped Vanadium Phosphorus Oxide (VPO) Catalyst: Effect of Ball Milling

2016 ◽  
Vol 7 (1) ◽  
pp. 73 ◽  
Author(s):  
Y.H. Taufiq-Yap ◽  
C.K. Goh
Keyword(s):  
Ball Milling ◽  
Surface Area ◽  
Surface Acidity ◽  
Milling Process ◽  
Surface Reactivity ◽  
Bet Surface Area ◽  
Phosphorus Oxide ◽  
Vanadium Phosphorus Oxide ◽  
Milled Material ◽  
Mn Doped

<p>The effect of ball milling on the structure and surface reactivity of the Mn-doped vanadium phosphorus oxide (V–P–O) catalyst is discussed. Mn-doped VOHPO<sub>4</sub>·½H<sub>2</sub>O precursor was prepared via organic method. The precursor was ball milled in isopropyl alcohol using agate balls for 60 min at 800 rpm. XRD, BET surface area measurements, SEM, O<sub>2</sub>-TPD, H<sub>2</sub>-TPR and TPD of NH<sub>3</sub> were used to characterize properties of the final catalysts. The results revealed that mechanical treatment of Mn-doped V–P–O catalyst increased surface area as well as reduced particle size of the material. Furthermore, process also increased exposure of (001) crystallographic plane of VOHPO4·½H<sub>2</sub>O precursor. The secondary structure of the milled material is also lost. The total amount of oxygen desorbed (from O<sub>2</sub>-TPD) and removed (by H<sub>2</sub>-TPR) from milled material is higher compared to the unmilled one. The surface acidity of the catalyst was also increased after milling process, as evidenced by lower desorption temperature and higher total amount of the ammonia desorbed.</p>

scholarly journals Physico–Chemical Characterization of Vanadium–Phosphorus–Oxide Catalysts Prepared in Organic and Aqueous Medium

2012 ◽  
Author(s):  
Yun Hin Taufiq–Yap ◽  
Ming–Hoong Looi ◽  
D. You–Ngiik Wong ◽  
Mohd. Zobir Hussien
Keyword(s):  
Aqueous Medium ◽  
Surface Area ◽  
Chemical Characterization ◽  
Bet Surface Area ◽  
Temperature Programmed Reduction ◽  
Phosphorus Oxide ◽  
Vanadium Phosphorus Oxide ◽  
Result Show ◽  
Temperature Programmed

Dua mangkin vanadium–fosforus–oksida (VPO) telah disediakan dengan menggunakan kaedah yang dikenali sebagai medium ‘organik’ dan ‘akueus’. Pencirian mangkin ini telah dilakukan dengan menggunakan luas permukaan BET dan keliangan, analisis gravimetrik terma (TGA/DTG) dan penurunan berprogram suhu (TPR). Hasil kajian menunjukkan mangkin VPO yang disediakan dalam media organik memiliki luas permukaan yang lebih besar, mobiliti oksigen kekisi yang lebih tinggi dan mempunyai tapak penurunan yang lebih banyak. Kata kunci: Vanadium-fosforus-oksida; pengoksidaan butana; penurunan berprogram suhu Two vanadium–phosphorus–oxide (VPO) catalysts were prepared by two different methods known as organic and aqueous medium. Characterization of these catalysts were carried out by BET surface area and porosity, gravimetry thermal analysis (TGA/DTG) and temperature programmed reduction (TPR). The result show that VPO catalyst prepared in organic medium gave larger surface area, higher lattice oxygen mobility and has a greater reduction site. Key words: Vanadium-Phosphorus-Oxide; butane oxidation; maleic anhydride; temperature-programmed reduction.

scholarly journals The Characterization of Heterogeneous Nanocatalyst of Biohydroxyapatite-Lithium and its Application for Converting Malapari Seed Oil (Milletia pinnata L.) to Biodiesel

2018 ◽  
Vol 34 (4) ◽  
pp. 1817-1823
Author(s):  
I. Nengah Simpen ◽  
I. Made Sutha Negara ◽  
Ni Made Puspawati
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Seed Oil ◽  
Surface Acidity ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
Average Particle ◽  
Bovine Bone ◽  
Heterogeneous Nanocatalyst ◽  
Surface Basicity

Heterogeneous nanocatalyst of biohydroxyapatite-lithium (HA-Li) has been prepared through modification of HA extracted from bovine bone waste with Li at various calcination temperatures (400-700oC). Characterizations of the heterogeneous catalysts were including surface acidity-basicity, functional groups, BET surface area, particle size, and surface morphology. Optimization of catalyst ratios (1-7%) with the best characterization was applied for converting Malapari seed oil (Milletia pinnata L.) to biodiesel. The characterization results showed that HA-Li catalyst calcinated at 600oChad the highest surface basicity and Lewis acid sites revealing specific functional group of O-Li at wavenumber of 1612.49 cm-1. BET surface area of HA-Li catalyst decreased with increased average particle size. SEM analysis suggested that morfology of catalysts formed stack of agglomerates. The highest yield of biodiesel obtained on a catalyst ratio of 5% was 88.16%. GC-MS analysis showed 10 peaks, and 5 of the peaks exhibiting the highest percentage area were identified as methyl oleic, methyl palmitic, methyl erusic, methyl stearic, and methyl linoleic.

Photocatalytic Activities under UV Light of Ball-Milled TiO2 Photocatalysts

2013 ◽  
Vol 802 ◽  
pp. 237-241 ◽  
Author(s):  
Jiravat Rattanarak ◽  
Wanichaya Mekprasart ◽  
Wisanu Pecharapa ◽  
Wicharn Techitdheera
Keyword(s):  
Ball Milling ◽  
Surface Area ◽  
Milling Time ◽  
Uv Light ◽  
Active Surface ◽  
Nitrogen Atmosphere ◽  
Milling Process ◽  
Active Surface Area ◽  
Ball Milling Process ◽  
Different Temperatures

Anatase TiO2powders used as photocatalysts were prepared by ball milling process at various milling time and annealed in nitrogen atmosphereat different temperatures. Commercial TiO2powders were ball-milled with ethanol at room temperature. After ball milling process, the samples were annealed in nitrogen atmosphere. The particle sizes and surface area of milled powders were measured by particle analyzer and Brunauer Emmet Teller method(BET). Effect of milling time and annealing temperature on structural properties of TiO2powders was investigated by X-ray diffraction(XRD) and scanning electron microscope(SEM). The degradation of aquous RhB dye by ball-milled TiO2powder photocatalyst was investigated under UV light irradiation. Comparing to P-25, TiO2powder prepared via ball milling process at 24 hr demonstrated significant enhancement in its photocatalytic activity under UV light due to the increasing active surface area after ball milling process.

scholarly journals Synthesis Method Effect of CoFe2O4on Its Photocatalytic Properties for H2Production from Water and Visible Light

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yudith Ortega López ◽  
Hugo Medina Vázquez ◽  
Jesús Salinas Gutiérrez ◽  
Vanessa Guzmán Velderrain ◽  
Alejandro López Ortiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Ball Milling ◽  
Synthesis Method ◽  
Milling Process ◽  
Bet Surface Area ◽  
Light Spectrum ◽  
Vis Spectroscopy ◽  
Adsorption Desorption

Currently, the need for more efficient materials that work in the visible light spectrum for hydrogen production has been increasing. Under this criterion, ferrites are ideal because their energetic properties are favorable to photocatalysis as they have a low band gap (1.5 to 3 ev). In this particular research, ferrite is presented as a hydrogen producer. Cobalt ferrites were synthesized by chemical coprecipitation (CP) and ball milling (BM) for comparison of their performance. The characterization of the materials was carried out with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, UV-VIS spectroscopy, and water adsorption/desorption tests. Evaluation of the photocatalytic activity under visible light was followed by gas chromatography. The results showed that cobalt ferrite by ball milling had a higher photocatalytic activity; this is attributed to the vacancies generated during the milling process at which the sample was exposed.

Effects of ball milling on the doped vanadium phosphorus oxide catalysts

2002 ◽  
Vol 74 (1-2) ◽  
pp. 101-110 ◽  
Author(s):  
Weijie Ji ◽  
Lijun Xu ◽  
Xiaoshu Wang ◽  
Zhen Hu ◽  
Qijie Yan ◽  
...  
Keyword(s):  
Ball Milling ◽  
Oxide Catalysts ◽  
Phosphorus Oxide ◽  
Vanadium Phosphorus Oxide

scholarly journals Vanadium Phosphorus Oxide/Siliceous Mesostructured Cellular Foams: efficient and selective for sustainable acrylic acid production via condensation route

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Liu ◽  
Peiwen Xu ◽  
Pengcheng Wang ◽  
Zhijia Xu ◽  
Xinzhen Feng ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Surface Acidity ◽  
Catalytic Performance ◽  
Phosphorus Oxide ◽  
Vanadium Phosphorus Oxide ◽  
Cellular Foams ◽  
New Type ◽  
Phase Regulation ◽  
First Time ◽  
Unique Surface

AbstractA new type of supported vanadium phosphorus oxide (VPO) with self-phase regulation was simply fabricated (organic solvent free) for the first time by depositing the specific VPO precursor NH4(VO2)HPO4 onto the Siliceous Mesostructured Cellular Foams (MCF) with controlled activation. The resulting materials were found to be highly efficient and selective for sustainable acrylic acid (AA) plus methyl acrylate (MA) production via a condensation route between acetic acid (HAc) and formaldehyde (HCHO). A (AA + MA) yield of 83.7% (HCHO input-based) or a (AA + MA) selectivity of 81.7% (converted HAc-based) are achievable at 360 °C. The systematic characterizations and evaluations demonstrate a unique surface regulation occurring between the MCF and the NH4(VO2)HPO4 precursor. NH3 release upon activation of NH4(VO2)HPO4 precursor together with adsorption of NH3 by MCF automatically induces partial reduction of V5+ whose content is fine-tunable by the VPO loading. Such a functionalization simultaneously modifies phase constitution and surface acidity/basicity of catalyst, hence readily controls catalytic performance.

Role of Organic Additives in Hydriding Properties of Mg-C Nanocomposites

2005 ◽  
Vol 494 ◽  
pp. 137-142 ◽  
Author(s):  
Amelia Montone ◽  
Jasna Grbović Novaković ◽  
A. Bassetti ◽  
L. Mirenghi ◽  
P. Rotolo ◽  
...  
Keyword(s):  
Ball Milling ◽  
Weight Ratio ◽  
Hydrogen Desorption ◽  
Rietveld Analysis ◽  
Organic Additive ◽  
Milling Process ◽  
Organic Additives ◽  
Composite Surface ◽  
Structural Modifications ◽  
Milled Material

The hydrogen storage performances of Mg-C nanocomposites have been studied on materials synthesized by ball milling with and without addition of an organic additive. The main purpose of this work is to study in more detail the cooperative effect observed when both graphite and benzene are added to the milled blend. In fact, when both components are added to Mg in the ball milling process, good catalyzing properties of the composite surface allow improved sorptiondesorption behavior of the synthesized material. The processed materials have been characterized by XRD to assess the details of the phase structure by Rietveld analysis, while surface features have been studied by XPS, which evidences structural modifications of both the surface Mg oxide and the graphite particles. The hydrogen desorption behavior has been correlated with the surface structure which appears to depend on the carbon to benzene ratio. Thermal stability and hydrogen desorption properties were investigated by DSC. Experimental results on nanocomposites with the same Mg to C weight ratio (70:30) show improved performances for a proper choice of carbon to benzene ratio weight (1/3), even after manipulation of the milled material in air.

Surface reactivity of A horizons towards polar compounds estimated from water adsorption and water content

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1105 ◽  
Author(s):  
R. L. Parfitt ◽  
J. S. Whitton ◽  
B. K. G. Theng
Keyword(s):  
Water Content ◽  
Surface Area ◽  
Water Adsorption ◽  
Polar Compounds ◽  
Water Area ◽  
Surface Reactivity ◽  
Bet Surface Area ◽  
Quick Method ◽  
Dry Water ◽  
Water Contents

The measurement of the specific surface area of soils may be useful for ranking soils in their ability to sorb polar compounds such as some pesticides and pollutants. For A horizons with varied mineralogy, particularly those containing large amounts of soil organic matter, this is problematic. We have estimated the surface area of a range of topsoils from water adsorption using the BET equation. The values obtained were greater than those measured from the adsorption of para-nitrophenol. There was a good relationship between the BET water area and the CEC of the samples (r2 = 0.83). There was a better relationship between the BET surface area and the water content of air-dry topsoils (r 2 = 0.98). We suggest that the air-dry water contents of topsoils could be used as a quick method to rank soils in order of their surface reactivity towards polar molecules, and this is preferable to more complicated methods.

Synthesis and Characterization of Florfenicol-silver Nanocomposite and its Antibacterial Activity against some Gram Positive and Gram-negative Bacteria

2020 ◽  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Zeta Potential ◽  
Surface Area ◽  
Spherical Shape ◽  
Bet Surface Area ◽  
Sonochemical Method ◽  
Raman Spectrometry ◽  
Silver Nanocomposite ◽  
Morphology Characterization

In this paper, easy, rapid and cheap synthetic method was described for florfenicol-silver nanocomposite by sonochemical method. Florfenicol-silver nanocomposite was characterized based on three classes namely index, identification and morphology class. Index characterization was carried out by zeta sizing, BET surface area and zeta potential. Identification characterization was performed using X-ray diffraction (XRD) and Raman spectrometry. Morphology characterization was done utilizing transmission electron microscope (TEM), scanning electron microscope (SEM) and atomic force microscope (AFM). Characterization results showed zeta sizing of florfenicol was 30.44nm, while florfenicol-silver nanocomposite was 33.5 nm with zeta potential -14.1 and -18, respectively. BET surface area was found to be 13.3, 73.2 and 103.69 m2/g for florfenicol, silver nanoparticles and florfenicol-silver nanocomposite respectively. XRD and Raman charts confirmed the formation of florfenicol-silver nanocomposite without any contamination. TEM, SEM and AFM spectral data illustrated spherical to sub spherical shape of silver nanoparticles on cubic to sheet shape of florfenicol with size less than 50 nm. Antimicrobial activity was screened where the average zone of inhibitions caused by the prepared nanocomposite were 28.3 mm, 24 mm, 27.3 mm and 24 mm compared to 17.7 mm, 16 mm, 18.7 mm and 13.3 mm of the native drug and 13 mm, 10 mm, 14.3 mm and 15 mm of the used positive reference standards against E. coli, Salmonella typhymurium, Staphylococcus aureus and Staph.aureus MRSA respectively.

Life Time Improvement of Hierarchically Structured SAPO-34 Nanocatalyst in MTO Reaction via Applying Clinoptilolite, Investigating of Composite Design via RSM

2020 ◽  
Vol 23 ◽  
Author(s):  
Reza Yazdanpanah ◽  
Eshagh Moradiyan ◽  
Rouein Halladj ◽  
Sima Askari
Keyword(s):  
Surface Area ◽  
Natural Zeolite ◽  
Coke Formation ◽  
Life Time ◽  
Weight Percent ◽  
Light Olefins ◽  
Bet Surface Area ◽  
Relative Crystallinity ◽  
Mto Reaction ◽  
The Common

Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time. Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel. Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure. Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.

Sign in / Sign up

Export Citation Format

Share Document