scholarly journals Graphene Nanoplatelets-Based Ni-Zeolite Composite Catalysts for Heptane Hydrocracking

2020 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
Roba Saab ◽  
Kyriaki Polychronopoulou ◽  
Nikolaos Charisiou ◽  
Maria A. Goula ◽  
Andreas Schiffer
Keyword(s):  
Water Adsorption ◽  
Catalyst Surface ◽  
Zeolite Y ◽  
Graphene Nanoplatelets ◽  
Bet Surface Area ◽  
Composite Catalysts ◽  
Texture Characteristics ◽  
Hydrophobic Nature ◽  
Two Temperatures ◽  
Zeolite Composite

This paper examines the effect of incorporating graphene nanoplatelets (GNPs) in an Ni-based/Zeolite-Y catalyst on the hydrocracking of heptane fuel at two temperatures, 350 and 400 °C. Specifically, reduced GNP/NiO-ZY and NiO-ZY catalysts, each with a 5 wt. % Ni loading, were compared in this study. The results show that the reduced GNP/NiO-ZY enhanced the conversion percentage by 31% at 350 °C and by 6% at 400 °C as compared with the reduced NiO-ZY, and the GNP/NiO-ZY also showed superior stability, reporting a less than 2% drop in conversion over 20 h of time-on-stream. The enhancement in performance is linked to the surface and texture characteristics of both catalysts. Although the calcined GNP/NiO-ZY possessed a lower Brunauer–Emmett–Teller (BET) surface area of 458 m2/g compared with 536 m2/g for the calcined NiO-ZY, it showed a more hydrophobic nature, as deduced from the water adsorption profiles, which corroborates the hypothesis that the increased affinity between the catalyst surface and heptane molecules during the reaction leads to an improved catalytic activity.

scholarly journals Oxidized BPL Carbons

1993 ◽  
Vol 10 (1-4) ◽  
pp. 75-84 ◽  
Author(s):  
S.S. Barton ◽  
M.J.B. Evans ◽  
J.A.F. Macdonald
Keyword(s):  
Nitric Acid ◽  
Surface Area ◽  
Water Adsorption ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Adsorption Sites ◽  
A Value ◽  
Nitrogen Desorption ◽  
Oxidized Carbon ◽  
Increasing Temperature

A series of oxidized carbons has been prepared by treatment of the carbon with concentrated nitric acid at various temperatures, and the surface and adsorption properties of the prepared carbons studied. Water adsorption was modelled using a recently derived equation capable of predicting a value for the primary adsorption sites on the surface of a microporous carbon while fitting the experimentally determined isotherm at high relative pressures. The concentration of primary sites was seen to increase with increasing temperature of oxidation. The very highly oxidized carbon samples were found to have a significantly lower BET surface area determined from nitrogen desorption at 77 K and higher apparent density measured from mercury displacement.

scholarly journals Sorption and mechanism studies of Cu2+, Sr2+ and Pb2+ ions on mesoporous aluminosilicates/zeolite composite sorbents

2020 ◽  
Vol 82 (5) ◽  
pp. 984-997
Author(s):  
Tatyana Kouznetsova ◽  
Andrei Ivanets ◽  
Vladimir Prozorovich ◽  
Ahmad Hosseini-Bandegharaei ◽  
Hai Nguyen Tran ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Surface Complexation ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Maximum Adsorption Capacity ◽  
Zeolite Nay ◽  
Inner Surface ◽  
Zeolite Composite

Abstract The research aimed to develop a novel mesoporous aluminosilicate/zeolite composite by the template co-precipitation method. The effect of aluminosilicate (AlSi) and zeolite (NaY) on the basic properties and adsorption capacity of the resultant composite was conducted at different mass ratios of AlSi/NaY (i.e., 5/90, 10/80, 15/85, 20/80, and 50/50). The adsorption characteristics of such composite and its feedstock materials (i.e., aluminosilicates and zeolite) towards radioactive Sr2+ ions and toxic metals (Cu2+ and Pb2+ ions) in aqueous solutions were investigated. Results indicated that BET surface area (SBET), total pore volume (VTotal), and mesopore volume (VMeso) of prepared materials followed the decreasing order: aluminosilicate (890 m2/g, 0.680 cm3/g, and 0.644 cm3/g) > zeolite (623 m2/g, 0.352 cm3/g, and 0.111 cm3/g) > AlSi/NaY (20/80) composite (370 m2/g, 0.254 cm3/g, and 0.154 cm3/g, respectively). The Langmuir maximum adsorption capacity (Qm) of metal ions (Sr2+, Cu2+, and Pb2+) in single-component solution was 260 mg/g, 220 mg/g, and 161 mg/g (for zeolite), 153 mg/g, 37.9 mg/g, and 66.5 mg/g (for aluminosilicate), and 186 mg/g, 140 mg/g, and 77.8 mg/g for (AlSi/NaY (20/80) composite), respectively. Ion exchange was regarded as a domain adsorption mechanism of metal ions in solution by zeolite; meanwhile, inner-surface complexation was domain one for aluminosilicate. Ion exchange and inner-surface complexation might be mainly responsible for adsorbing metal ions onto the AlSi/NaY composite. Pore-filling mechanism was a less important contributor during the adsorption process. The results of competitive adsorption under binary-components (Cu2+ and Sr2+) and ternary-components (Cu2+, Pb2+, and Sr2) demonstrated that the removal efficacy of target metals by the aluminosilicate, zeolite, and their composite remarkably decreased. The synthesized AlSi/NaY composite might serve as a promising adsorbent for real water treatment.

scholarly journals Sustainable Production of Hydrogen by Steam Reforming of Ethanol Using Cobalt Supported on Nanoporous Zeolitic Material

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1934
Author(s):  
Javier Francisco da Costa-Serra ◽  
Maria Teresa Navarro ◽  
Fernando Rey ◽  
Antonio Chica
Keyword(s):  
Steam Reforming ◽  
Zeolite Y ◽  
Cobalt Catalysts ◽  
Coke Deposition ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Y Zeolite ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

Cobalt catalysts supported on Y zeolite and mesoporized Y zeolite (Y-mod) have been studied in steam reforming of ethanol (SRE). Specifically, the effect of the mesoporosity and the acidity of the y zeolite as a support has been explored. Mesoporous were generated on Y zeolite by treatment with NH4F and the acidity was neutralized by Na incorporation. Four cobalt catalysts supported on Y zeolite have been prepared, two using Y zeolite without mesoporous (Co/Y, Co/Y-Na), and two using Y zeolite with mesoporous (Co/Y-mod and Co/Y-mod-Na). All catalysts showed a high activity, with ethanol conversion values close to 100%. The main differences were found in the distribution of the reaction products. Co/Y and Co/Y-mod catalysts showed high selectivity to ethylene and low hydrogen production, which was explained by their high acidity. On the contrary, neutralization of the acid sites could explain the higher hydrogen selectivity and the lower ethylene yields exhibited by the Co/Y-Na and Co/Y-mod-Na. In addition, the physicochemical characterization of these catalysts by XRD, BET surface area, temperature-programmed reduction (TPR), and TEM allowed to connect the presence of mesoporous with the formation of metallic cobalt particles with small size, high dispersion, and with high interaction with the zeolitic support, explaining the high reforming activity exhibited by the co/y-mod-Na sample as well as its higher hydrogen selectivity. It has been also observed that the formation of coke is affected by the presence of mesoporous and acidity. Both properties seem to have an opposite effect on the reforming catalyst, decreasing and increasing the coke deposition, respectively.

Novel Base Catalysts by Nitridation of Zeolite Y: Characterization and Catalytic Evaluation

2010 ◽  
Vol 148-149 ◽  
pp. 1096-1099
Author(s):  
Gong Ming Peng ◽  
De Lian Yi ◽  
Lin Wu ◽  
Zhao Hui Ou Yang ◽  
Jian Guo Wang
Keyword(s):  
Surface Area ◽  
Zeolite Y ◽  
High Surface ◽  
High Surface Area ◽  
Diethyl Malonate ◽  
Bet Surface Area ◽  
In Situ Drifts ◽  
Base Catalysts ◽  
Diffuse Reflectance Infrared

Novel base catalysts were obtained by subjecting Y zeolites to nitridation. These materials were characterized by elemental analysis, X-ray diffraction, BET surface area analysis, In situ diffuse reflectance infrared fourier transform Spectroscopy (in situ DRIFTS), Pyrrole adsorption. The results indicated nitrogen-incorporated NaY zeolite was well ordered and possess high surface area and pore volume. In situ DRIFTS experiments confirmed that N atoms had been introduced into the framework by nitridation to form -NH2- or -NH- species. It was found that Lewis basicity of these oxynitride materials increased by the pyrrole adsorption. Furthmore, the basic catalytic properties of nitrogen-incorporated zeolites were evaluated by Knoevenagal condensation of benzaldehyde with diethyl malonate and enhanced yield of product was achieved.

Adsorption of water molecules on the surface of photo-catalyst: a first principles theoretical comparison between InVO4 and rutile TiO2

2002 ◽  
Vol 751 ◽  
Author(s):  
M. Oshikiri ◽  
M. Boero ◽  
J. Ye
Keyword(s):  
First Principles ◽  
Water Adsorption ◽  
Adsorption Process ◽  
Catalyst Surface ◽  
Chemical Reactivity ◽  
Water Molecules ◽  
Activation Energy Barrier ◽  
Reaction Proceeds ◽  
Adsorption Of Water ◽  
Dynamics Simulations

ABSTRACTThe adsorption process of water molecules on the surface of InVO4 has been investigated via first principles molecular dynamics simulations and compared with that of the well-known rutile TiO2. We have found that the surface of InVO4 shows a remarked chemical reactivity whenever comes in contact with water and H2O molecules are often adsorbed dissociatively on its surface. The reaction proceeds spontaneously in a way similar to the case of TiO2 and does not require the overcoming of an activation energy barrier. The peculiar atomic connectivity of the InVO4 bulk crystal structure and the changes at the catalyst surface induced by the water adsorption are discussed and compared with the TiO2 system.

scholarly journals Microwave-Assisted Adsorptive Desulfurization of Model Diesel Fuel Using Synthesized Microporous Rare Earth Metal-Doped Zeolite Y

2015 ◽  
Vol 12 (1) ◽  
pp. 44
Author(s):  
N. Salahudeen ◽  
A.S. Ahmed ◽  
A.H. Al-Muhtaseb ◽  
B.Y. Jibril ◽  
R. Al-Hajri ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metal ◽  
Zeolite Y ◽  
Earth Metal ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Adsorptive Desulfurization ◽  
Microwave Assisted ◽  
Desulfurization Process ◽  
Metal Doped

The microwave-assisted adsorptive desulfurization of model fuel (thiophene in n-heptane) was investigated using a synthesized rare earth metal-doped zeolite Y (RE Y). Crystallinity of the synthesized zeolite was 89.5%, the silicon/aluminium (Si/Al) molar ratio was 5.2, the Brunauer–Emmett–Teller (BET) surface area was 980.9 m2/g, and the pore volume and diameter was 0.3494 cm3/g and 1.425 nm, respectively. The results showed that the microwave reactor could be used to enhance the adsorptive desulfurization process with best efficiency of 75% at reaction conditions of 100 °C and 15 minutes. The high desulfurization effect was likely due to the higher efficiency impact of microwave energy in the interaction between sulfur in thiophene and HO-La(OSiAl).

Study of water adsorption on EDTA dealuminated zeolite Y

2020 ◽  
Vol 302 ◽  
pp. 110208
Author(s):  
Oleksii Pliekhov ◽  
Olena Pliekhova ◽  
Iztok Arčon ◽  
Federica Bondino ◽  
Elena Magnano ◽  
...  
Keyword(s):  
Water Adsorption ◽  
Zeolite Y

scholarly journals Assessment of the Location of Pt Nanoparticles in Pt/zeolite Y/γ‐Al 2 O 3 Composite Catalysts

ChemCatChem ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 615-622 ◽  
Author(s):  
Jogchum Oenema ◽  
Jan P. Hofmann ◽  
Emiel J. M. Hensen ◽  
Jovana Zečević ◽  
Krijn P. Jong
Keyword(s):  
Zeolite Y ◽  
Pt Nanoparticles ◽  
Composite Catalysts

Scope of Metal Loaded Microporous Zeolite-Y as Catalyst in Ozone Initiated Oxidation of n-hexadecane

2009 ◽  
Vol 12 (2) ◽  
Author(s):  
V. S. R. Rajasekhar Pullabhotla ◽  
S. B. Jonnalagadda
Keyword(s):  
Metal Ion ◽  
Zeolite Catalyst ◽  
Catalyst Surface ◽  
Zeolite Y ◽  
Y Zeolite ◽  
Substrate Molecule ◽  
Zeolite Support ◽  
Active Intermediate ◽  
Plausible Mechanism ◽  
Microporous Zeolite

AbstractThe efficiency of metal loaded microporous materials, zeolite-Y as catalysts in the ozone initiated oxy-functionalisation of long chained n-alkanes is investigated at moderate temperature (20 ± 1 °C) and pressure conditions (1 atm.). The efficiencies of 0.5% Pd, Ni, V and U loaded microporous zeolite-Y catalysts on ozonation of higher alkanes (n-hexadecane), with respect to the conversion and transformation towards keto products are compared. In the catalysed ozonation, n-hexadecane is converted to 4-, 3- and 2- keto isomers as major products with varied selectivity and % conversions. A plausible mechanism assuming the chemisorption of the substrate molecule on the catalyst surface and further electron transfer between the metal ion loaded on the zeolite support and the active intermediate formed in course of reaction for the ozone initiated oxidation of n-hexadecane with heterogeneous Ni loaded Na-Y zeolite catalyst is proposed.

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