scholarly journals Highly porous hydroxyapatite derived from cuttlefish bone as tio2 catalyst support

2018 ◽  
Vol 12 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Dajana Milovac ◽  
Ivna Weigand ◽  
Marin Kovacic ◽  
Marica Ivankovic ◽  
Hrvoje Ivankovic
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalyst Support ◽  
Vacuum Impregnation ◽  
Porous Hydroxyapatite ◽  
Tio2 Catalyst ◽  
Bet Method ◽  
Highly Porous

Highly porous hydroxyapatite (Ca10(PO4)6(OH)2, HAp) catalyst support was prepared through hydrothermal transformation of aragonitic cuttlefish bone (Sepia Officinalis, L., Adriatic Sea) at 200?C, preserving the natural well interconnected porous structure. To deposit the TiO2 catalyst on the pore walls of the HAp support two methods were used: i) vacuum impregnation of the support with the suspension of a commercial TiO2 nanopowder in isopropanol and ii) in situ synthesis of TiO2 on the support by sol-gel technique. XRD analysis and FTIR spectroscopy were used to determine the phase composition of the material. The morphology and microstructure of the composite samples were studied by scanning electron microscopy (SEM). The presence of TiO2 particles on the HAp surface was determined by SEM/EDX analysis. To determine the specific surface area and pore size, Brunauer-Emmett-Teller (BET) method was used. The results of the BET method showed the increased specific surface area and pore size reduction after impregnation of TiO2 into the HAp carrier. The photocatalytic activity of HAp/TiO2 samples was studied in a batch reactor with an annular UV-A lamp using salicylic acid as a model water pollutant. The results indicated the suitability of prepared HAp supported TiO2 catalysts for photocatalytic applications.

scholarly journals Investigation of Salt and precipitating agent effect on the specific surface area and compressive strength of alumina catalyst support

2017 ◽  
Vol 19 (3) ◽  
pp. 35-40 ◽  
Author(s):  
Mostafa Mahmoudian ◽  
Alireza Hemmati ◽  
Hasan Hashemabadi ◽  
Ahad Ghaemi ◽  
Shahrokh Shahhosseini
Keyword(s):  
Compressive Strength ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Catalyst Support ◽  
Catalyst Supports ◽  
Chloride Salt ◽  
Alumina Catalyst

Abstract Nowadays, catalyst supports are extensively used to decrease the costs and increase the contact surface area in chemical reactions. Specific surface area, compressive strength, pore volume and pore size are some of the most important characteristics of a catalyst support. In this work, Sol-gel and peptization methods were applied to produce alumina catalyst support. Also the roles of aluminum salts and precipitating agents on the specific surface area and compressive strength of alumina catalyst support were investigated. In addition, various additives and common methods in the increasing surface area, compressive strength and adjusting the porosity and pore size are used in this study. The results show that using caustic soda as precipitating agent and aluminum chloride salt yields catalyst supports with the best compressive strength. Also, using aluminum nitrate and ammonia as precipitating agent produced alumina catalyst support with the highest specific surface area.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

scholarly journals Influence of the Calcination Temperature on the properties of The Alumina as Catalyst Support for Catalysis

Paliva ◽  
2020 ◽  
pp. 155-161
Author(s):  
Tomáš Hlinčík ◽  
Veronika Šnajdrová ◽  
Veronika Kyselová
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Calcination Temperature ◽  
Specific Surface Area ◽  
Catalyst Support ◽  
Chemical Properties ◽  
Total Pore Volume ◽  
Temperature Range ◽  
Calcination Temperatures ◽  
Physical And Chemical

Alumina is commonly used in industrial practice as a catalyst support and it is made from boehmite. Depending on the calcination temperature, this mineral is transformed into various crystalline modifications which have different physical and chemical properties. For this reason, the following parameters were determined at different calcination temperatures: length, width, material hardness, specific surface area and total pore volume. The results show that with increasing calcination temperature there have been significant changes which may be important when using the material as a catalyst support, e.g. in the preparation of catalysts or in the design of cat-alytic reactors. The specific surface area, which decreases in the temperature range 450–800 °C, is an important parameter for the preparation of catalysts, so it is appropriate to choose a temperature of 600 °C, when the specific surface area is above 200 m2·g-1. The effect of calcination temperature on the structural transitions of boehmite was also monitored. The results showed that γ-Al2O3 has the most suitable properties as a catalyst sup-port in the temperature range 450–800 °C.

Mesoporous Activated Carbon Filaments

1996 ◽  
Vol 454 ◽  
Author(s):  
Weiming Lu ◽  
D. D. L. Chung
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mesoporous Activated Carbon ◽  
Carbon Filaments

ABSTRACTActivated carbon filaments of diameter ∼0.1 μm, main pore size (BJH) 55 Å, specific surface area 1310 m2/g and yield 36.2% were obtained by activating carbon filaments of diameter ∼ 0.1 urn in C02 + N2 (1:1) at 970°C for 80 min. Prior to this activation, the filaments were surface oxidized by exposure to ozone.

High specific surface area ordered mesoporous silica COK-12 with tailored pore size

2019 ◽  
Vol 280 ◽  
pp. 133-143 ◽  
Author(s):  
Laura M. Henning ◽  
Diego Díaz Cubas ◽  
Maria G. Colmenares ◽  
Johannes Schmidt ◽  
Maged F. Bekheet ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Ordered Mesoporous Silica ◽  
Ordered Mesoporous

Preparation of Porous Wollastonite Ceramics for Filtration

2007 ◽  
Vol 336-338 ◽  
pp. 1102-1104 ◽  
Author(s):  
Ming Sheng He ◽  
Jian Bao Li ◽  
Bo Wen Li ◽  
Hong Lin ◽  
Xiao Zhan Yang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sintering Temperature ◽  
Porous Ceramics ◽  
Holding Time ◽  
Starting Material ◽  
Sintering Method

Wollastonite powder was selected as a starting material with carbonate as pore-forming agent and binder added. The porous ceramics were prepared at different temperature by sintering method. The process includes batching, granulating, pressing molding, drying and sintering. It is discussed the influence of sintering temperature, dosage of binder, dosage of pore-forming agent, pressure of molding and holding time on the performance of porous ceramics. According to the principle of particles stack, the porous wollastonite ceramics for filtration with various diameters, shapes and porosity were fabricated by serial experiments. These products have 1 to 10 microns in pore size, 30.04 to 66.15% in porosity, 2.82 m2/g in specific surface area.

scholarly journals A combustion method to synthesize nanoporous graphene

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9320-9326
Author(s):  
Q. Y. Yang ◽  
H. L. Zhou ◽  
M. T. Xie ◽  
P. P. Ma ◽  
Z. S. Zhu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Combustion Process ◽  
Combustion Method ◽  
Nanoporous Graphene

The combustion process of GOA, and the specific surface area and pore size distribution of P-RGO are shown in the images.

scholarly journals Novel Activated Carbon Nanofibers Composited with Cost-Effective Graphene-Based Materials for Enhanced Adsorption Performance toward Methane

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2064
Author(s):  
Faten Ermala Che Othman ◽  
Norhaniza Yusof ◽  
Noorfidza Yub Harun ◽  
Muhammad Roil Bilad ◽  
Juhana Jaafar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Activated Carbon ◽  
Specific Surface ◽  
Pore Size ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Carbon Nanofibers ◽  
Specific Surface Area ◽  
Activated Carbon Nanofibers ◽  
Reduced Graphene

Various types of activated carbon nanofibers’ (ACNFs) composites have been extensively studied and reported recently due to their extraordinary properties and applications. This study reports the fabrication and assessments of ACNFs incorporated with graphene-based materials, known as gACNFs, via simple electrospinning and subsequent physical activation process. TGA analysis proved graphene-derived rice husk ashes (GRHA)/ACNFs possess twice the carbon yield and thermally stable properties compared to other samples. Raman spectra, XRD, and FTIR analyses explained the chemical structures in all resultant gACNFs samples. The SEM and EDX results revealed the average fiber diameters of the gACNFs, ranging from 250 to 400 nm, and the successful incorporation of both GRHA and reduced graphene oxide (rGO) into the ACNFs’ structures. The results revealed that ACNFs incorporated with GRHA possesses the highest specific surface area (SSA), of 384 m2/g, with high micropore volume, of 0.1580 cm3/g, which is up to 88% of the total pore volume. The GRHA/ACNF was found to be a better adsorbent for CH4 compared to pristine ACNFs and reduced graphene oxide (rGO/ACNF) as it showed sorption up to 66.40 mmol/g at 25 °C and 12 bar. The sorption capacity of the GRHA/ACNF was impressively higher than earlier reported studies on ACNFs and ACNF composites. Interestingly, the CH4 adsorption of all ACNF samples obeyed the pseudo-second-order kinetic model at low pressure (4 bar), indicating the chemisorption behaviors. However, it obeyed the pseudo-first order at higher pressures (8 and 12 bar), indicating the physisorption behaviors. These results correspond to the textural properties that describe that the high adsorption capacity of CH4 at high pressure is mainly dependent upon the specific surface area (SSA), pore size distribution, and the suitable range of pore size.

Sign in / Sign up

Export Citation Format

Share Document