Hydrothermal Synthesis and Adsorption Proprieties of Titania-Active Carbon Composites

2010 ◽  
Vol 150-151 ◽  
pp. 391-395
Author(s):  
Yue Luo ◽  
Xue Min Yan ◽  
Huan Yang ◽  
Gao Shen Su

Titania nanoparticles were anchored onto active carbon (AC) through a hydrothermal process to obtain TiO2/AC composites. The optimal TiO2 loading and hydrothermal pH were investigated. The prepared TiO2/AC composites were used as adsorbents for dibenzothiophene (DBT) from model fuel. The adsorption capacity of TiO2/AC composite in the optimal synthesis conditions has enhanced 12.4% compared with pure AC. The adsorbents were regenerated by toluene washing, and the TiO2/AC composite showed higher adsorptive capacity than AC even after three recycles. The pore structure and surface chemical proprieties of TiO2/AC composite and AC were also investigated by N2 adsorption-desorption isotherms and Beohm titration. The results indicate that the surface acidic sites of TiO2/AC may play an important role in the improved adsorption performance.

2020 ◽  
Vol 4 (4) ◽  
pp. 1-3
Author(s):  
Liu L

The mesoporous ZSM-5 zeolite containing MoCoP/Al2O3 catalyst (C12-ZSM5) with the mixture of Al2O3 and mesoporous ZSM- 5 zeolite as carrier was synthesized. The catalytic performance of C12-ZSM5 catalyst was evaluated by the hydrodesulfurization (HDS) of different diesel feedstock. The carriers and catalysts were characterized by N2 adsorption-desorption, pyridine-FTIR, X-ray diffraction (XRD) and CO in-situ FTIR (CO-FTIR) techniques. Results showed that mesoporous ZSM-5 can improve the acidity of the catalyst and increase the number of MoCoS active phases. The C12-ZSM5 catalyst had low HDS and HDN activity, because the acidic sites of mesoporous ZSM-5 were easily occupied by nitrogen compounds. The HDS activity of C12-ZSM5 catalyst was fully exploited by using graded packing technology, the sulfur content of product oil was 5.9 ng/μL. The relative HDS activity of C12-ZSM5 catalyst is 1.47 times that of FHUDS-8 catalyst.


2005 ◽  
Vol 30 (4) ◽  
pp. 43-49 ◽  
Author(s):  
J. C. P Vaghetti ◽  
J. L. Brasil ◽  
T. M. H Costa ◽  
E. C. Lima ◽  
E.V Benvenutti

The hybrid 3-(1,4-phenylenediamine)propylsilica xerogel was obtained starting from two different organic precursor quantity (5 and 8 mmol) to 22 mmol of TEOS, in the synthesis. The xerogel samples were characterized by using CHN elemental analysis, N2 adsorption-desorption isotherms, infrared thermal analysis. The xerogel was used as metal sorbent for Cu2+, Cd2+ and Pb2+ in aqueous solution with concentration range of 10-3 to 10-5 mmol l-1. The quantity of organic precursor added in the synthesis influences the characteristics of the xerogel as morphology and thermal stability, as well as the metal adsorption capacity.


Author(s):  
Dey Kamol

This paper demonstrated the preparation of flower-like TiO2 nanostructures by low temperature hydrothermal process from TiO2 nanoparticles. The as-synthesized TiO2 nanoparticles and flower-like TiO2 nanostructures were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption-desorption measurements. The flower-like TiO2 nanostructures possessed good crystallinity, showed fairly large surface area of 220 m2/g and exhibited better photocatalytic degradation of rhodamine B than TiO2 nanoparticles under simulated solar radiation.


Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 488
Author(s):  
Katarzyna Stawicka ◽  
Maciej Trejda ◽  
Maria Ziolek

Niobium containing SBA-15 was prepared by two methods: impregnation with different amounts of ammonium niobate(V) oxalate (Nb-15/SBA-15 and Nb-25/SBA-15 containing 15 wt.% and 25 wt.% of Nb, respectively) and mixing of mesoporous silica with Nb2O5 followed by heating at 500 °C (Nb2O5/SBA-15). The use of these two procedures allowed obtaining materials with different textural/surface properties determined by N2 adsorption/desorption isotherms, XRD, UV-Vis, pyridine, and NO adsorption combined with FTIR spectroscopy. Nb2O5/SBA-15 contained exclusively crystalline Nb2O5 on the SBA-15 surface, whereas the materials prepared by impregnation had both metal oxide and niobium incorporated into the silica matrix. The niobium species localized in silica framework generated Brønsted (BAS) and Lewis (LAS) acid sites. The inclusion of niobium into SBA-15 skeleton was crucial for the achievement of high catalytic performance. The strongest BAS were on Nb-25/SBA-15, whereas the highest concentration of BAS and LAS was on Nb-15/SBA-15 surface. Nb2O5/SBA-15 material possessed only weak LAS and BAS. The presence of the strongest BAS (Nb-25/SBA-15) resulted in the highest dehydration activity, whereas a high concentration of BAS was unfavorable. Silylation of niobium catalysts prepared by impregnation reduced the number of acidic sites and significantly increased acrolein yield and selectivity (from ca. 43% selectivity for Nb-25/SBA-15 to ca. 61% for silylated sample). This was accompanied by a considerable decrease in coke formation (from 47% selectivity for Nb-25/SBA-15 to 27% for silylated material).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Özge Balcı ◽  
Merve Buldu ◽  
Ameen Uddin Ammar ◽  
Kamil Kiraz ◽  
Mehmet Somer ◽  
...  

AbstractBoron carbide powders were synthesized by mechanically activated annealing process using anhydrous boron oxide (B2O3) and varying carbon (C) sources such as graphite and activated carbon: The precursors were mechanically activated for different times in a high energy ball mill and reacted in an induction furnace. According to the Raman analyses of the carbon sources, the I(D)/I(G) ratio increased from ~ 0.25 to ~ 0.99, as the carbon material changed from graphite to active carbon, indicating the highly defected and disordered structure of active carbon. Complementary advanced EPR analysis of defect centers in B4C revealed that the intrinsic defects play a major role in the electrochemical performance of the supercapacitor device once they have an electrode component made of bare B4C. Depending on the starting material and synthesis conditions the conductivity, energy, and power density, as well as capacity, can be controlled hence high-performance supercapacitor devices can be produced.


Author(s):  
Maciej Trejda ◽  
Magdalena Drobnik ◽  
Ardian Nurwita

AbstractMesoporous silica of SBA-15 type was modified for the first time with 3-(trihydroxysiyl)-1-propanesulfonic acid (TPS) by post-synthesis modification involving microwave or conventional heating in order to generate the Brønsted acidic centers on the material surface. The samples structure and composition were examined by low temperature N2 adsorption/desorption, XRD, HRTEM, elemental and thermal analyses. The surface properties were evaluated by esterification of acetic acid with n-hexanol used as the test reaction. A much higher efficiency of TPS species incorporation was reached with the application of microwave radiation for 1 h than conventional modification for 24 h. It was found that the structure of mesoporous support was preserved after modification using both methods applied in this study. Materials obtained with the use of microwave radiation showed a superior catalytic activity and high stability.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


2013 ◽  
Vol 448-453 ◽  
pp. 169-173
Author(s):  
Chun Yan Yan ◽  
Wen Tao Yi

Pure and F, Fe-codoped TiO2 were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO3)2·6H2O and NH4F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO2. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO2 had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.


2019 ◽  
Vol 41 (1) ◽  
pp. 72-72
Author(s):  
Jilei Liang Jilei Liang ◽  
Mengmeng Wu Mengmeng Wu ◽  
Hongmei Cai Hongmei Cai ◽  
Hao Wang Hao Wang ◽  
Hua Huang Hua Huang ◽  
...  

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 and#176;C dominates the adsorption capacity for acetic acid.


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