Synthesis of Carbon Nanofiber-Titania-Cordierite Monolith Composite and its Application as Catalyst Support on Citral Hydrogenation

2012 ◽  
Vol 535-537 ◽  
pp. 178-185 ◽  
Author(s):  
Jie Zhu ◽  
Ming Shi Li ◽  
Mo Hong Lu
Keyword(s):  
Surface Area ◽  
Carbon Nanofiber ◽  
Sol Gel ◽  
Catalyst Support ◽  
Textural Properties ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Citral Hydrogenation

We reported the synthesis of a promising carbon nanofiber-titania-cordierite monolith composite (C/TiO2/monolith) and its application in citral hydrogenation. The composite was synthesized through two steps: TiO2 coating on the surface of the monolith with sol-gel method and the following carbon deposit by methane decomposition. C/TiO2/monolith was subsequently employed to prepare its supported palladium catalyst, Pd/C/TiO2/monolith and its catalytic performance was evaluated in selective hydrogenation of citral. Results revealed that 2.0 wt% tetrabutyl titanate sol in composite synthesis was the best in improving textural properties of C/TiO2/monolith. The optimal composite possessed a BET surface area of 39.4 m2/g and micropore area accounted for only 3.8% of its total BET surface area. It contained about 30 wt% of carbon, which was mainly composed of carbon nanofiber. Pd/C/TiO2/monolith exhibited the high citronellal selectivity (81%) at 90% citral conversion, which was attributed to the decrease of internal diffusion limitation due to its mesoporous structure.

Sol-gel Preparation of Hollow Spherical x%B-TiO2 Photocatalyst: The Effect of Boron Content on RBR X-3B Decoloration

2018 ◽  
Vol 14 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Wenjie Zhang ◽  
Yuxuan Liu ◽  
Hongliang Xin
Keyword(s):  
Surface Area ◽  
Oxidation State ◽  
Boron Content ◽  
Sol Gel ◽  
Boron Doping ◽  
Anatase Tio2 ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Doping Content ◽  
X Ray

Background: The potential of applying TiO2-based materials has been ascertained in both wastewater and polluted air. Boron is proven to be an effective dopant to promote the activity of TiO2 in our previous work. The density of hollow material is little larger than water so that the hollow photocatalyst can suspend in wastewater under stirring or aeration. Methods: The graphical spheres were prepared from glucose using hydrothermal method. The hollow spherical x%B-TiO2 was synthesized through a sol-gel route, using tetrabutyl titanate and tributyl borate in the precursor. The materials were characterized by X-ray diffraction, scanning electron microscope, infrared spectrum, X-ray photoelectron spectroscopy, and N2 adsorption-desorption techniques. Photocatalytic degradation of RBR X-3B dye was studied to show the activity of the x%B-TiO2 materials. Results: Anatase TiO2 phase forms in all the x%B-TiO2 samples despite the difference in boron content. An absolute Ti4+ oxidation state exists in the x%B-TiO2, which is hardly affected by the doped boron. XPS analysis proves the formation of B-Ti-O structure in anatase TiO2 lattice. BET surface area increases with rising boron doping content in the hollow spherical x%B-TiO2 samples. Photocatalytic activity of TiO2 is enhanced after doping boron. The photocatalytic efficiency on RBR X- 3B degradation reaches the maximum value when n(B)/n(Ti) is 8%. After five photocatalytic cycles, decoloration efficiency on 8%B-TiO2 is as much as 80% of the initial value. Conclusion: A continuous expansion of TiO2 crystal happens with increasing boron content. The Ti4+ oxidation state of titanium in the hollow spherical material is not changed after doping boron. BET surface area of the hollow spherical x%B-TiO2 increases with rising boron doping content. The hollow spherical 8%B-TiO2 has satisfactory performs for recycling and lifetime.

Preparation and Characterization of Activated Carbon Fiber Supported Nano-TiO2

2012 ◽  
Vol 503-504 ◽  
pp. 646-649
Author(s):  
Xiao Ling Guo ◽  
Xiang Dong Wang ◽  
De Ping Ben
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Surface Area ◽  
Anatase Phase ◽  
Sol Gel ◽  
Activated Carbon Fiber ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Nano Tio2 ◽  
Mean Size

Nano-TiO2 powders were synthesized by a sol-gel method using tetrabutyl titanate as the precursor, and then the composites of ACF(activated carbon fiber) supported nano-TiO2 was prepared by impregnating method. Tests of the amount of loaded TiO2 showed that three impregnating times was adequate. The Nano-TiO2 powders and composites were characterized by XRD, SEM, and BET surface area method. XRD tests showed that nano-TiO2 powders prepared by this way are anatase phase, and the mean size of the particles is about 11.5nm, when the calcination temperature is 673K. BET results showed that compared with original ACF, the surface area of the composites decreased slightly, indicating the impregnating process did not change the porous structure of original ACF. SEM result indicated that most of the nano-TiO2 particles as the size of 10-20nm were homogeneously dispersed on the surface of ACF.

Preparation and Properties of Zno/Vermiculite Composite Particles

2012 ◽  
Vol 455-456 ◽  
pp. 265-270 ◽  
Author(s):  
Ling Jin ◽  
Bin Dai
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
Catalyst Support ◽  
High Surface Area ◽  
Xrd Analysis ◽  
Area Measurement ◽  
Photocatalytic Decomposition ◽  
Bet Surface Area ◽  
Effect Of Support

ZnO/vermiculite as the novel photocatalysts were prepared by two approachs: one is mixtures of ZnO and different acid treated vermiculite, and another is sol-gel method. The acid activated vermiculite as a new promising catalyst support and adsorbent has a large capacity of absorption, high surface area and thermal stability. The activity of catalyst has been interrelated to support and ZnO. Based on the important effect of support on ZnO/vermiculite photocatalysts, treatment of vermiculite by nitric acid of different concentration was studied by evaluated in the photocatalytic decomposition of MB with resulting photocatalysts. BET surface area measurement and X-ray diffraction (XRD) analysis were used to characteristic of ZnO particle in acid treated vermiculite structure and the phase structure and crystallization index of ZnO in the modified vermiculite mineral. Results showed the ZnO-vermiculite combination possessing higher photocatalytic activity due to the synergistic effect when compared to the commercial ZnO.

scholarly journals Preparation of Stellerite Loading Titanium Dioxide Photocatalyst and Its Catalytic Performance on Methyl Orange

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Hua Chen ◽  
Jianhua Wang ◽  
Huajun Wang ◽  
Fei Yang ◽  
Jia-nan Zhou ◽  
...  
Keyword(s):  
Surface Area ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Photocatalytic Ability ◽  
X Ray ◽  
Composite Photocatalysts ◽  
Ft Ir ◽  
Better Than

TiO2/stellerite composite photocatalysts were prepared by dispersing TiO2 onto the surface of HCl, NaOH, or NaCl treated stellerite using a sol-gel method. The materials were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), BET surface area analysis, and X-ray diffraction (XRD). HCl and NaCl modification result in the promotion of the pore formation at the stellerite surfaces and induced the microscopic changes, while the surface morphology and structure of the stellerite were almost ruined by NaOH modification. Supported TiO2 calcinated at 200°C presented anatase structure. The photocatalytic degradation activities of TiO2 loaded HCl and NaCl modified stellerite were better than that of natural stellerite, accompanied with increasing specific surface area. On the contrary, NaOH modification induced the loss of photocatalytic ability of composite due to the generation of silicates.

Synthesis of Mesoporous Nickel Phosphate with Long Hollow Nanotubes

2011 ◽  
Vol 399-401 ◽  
pp. 625-628 ◽  
Author(s):  
Juan Tan ◽  
Xu Ying Li ◽  
Fei Yang ◽  
Jing Liu
Keyword(s):  
Surface Area ◽  
Pore Volume ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
N2 Adsorption ◽  
Gel Method ◽  
Sol Gel Method ◽  
Nickel Phosphate ◽  
Ft Ir

Mesostructured nickel phosphate was synthesized with urea as alkali by sol-gel method. The obtained material nominated as NiPO-3 was characterized by means of XRD, ICP, FT-IR, TEM, and N2 adsorption. In contrast to mesoporous nickel phosphate NiPO-1 and NiPO-2 we reported before, NiPO-3 exhibits relatively longer nanotubes reached up to 400~600 nm. N2 adsorption shows that NiPO-3 possesses high BET surface area (345.8 m2g-1) and pore volume (0.46 cm3g-1). The catalytic performance of NiPO-3 showed that the total selectivity of epoxycyclohexane and hexadienol was as high as 83.38%.

Effects of Calcination on Sol-gel Synthesis of Hollow Spherical 8%B-TiO2 for Photocatalytic Degradation of RBR X-3B -Characterization and Activity

2019 ◽  
Vol 15 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Lili Yang ◽  
Yao Zhao ◽  
Jing Li ◽  
Yanwen Zhou ◽  
Xuan Xiao ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Surface Area ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Degradation Process ◽  
Maximum Activity ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Tio2 Sample ◽  
Small Surface

Background: TiO2-based materials can be utilized in both polluted air and wastewater treatments. Ion doping is the most applied modification method, and many kinds of metal ions and nonmetal ions are doped into a TiO2 crystalline skeleton. The hollow spherical photocatalyst can both easily suspend in wastewater under aeration and settle down after treatment to release the water. Methods: The hollow spherical B-TiO2 photocatalyst was prepared by a sol-gel method. Tetrabutyl titanate and tributyl borate were used as the titanium and boron sources. The materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), infrared spectrum (FTIR), and N2 adsorption-desorption techniques. Results: The 8%B-TiO2 material is composed of anatase TiO2 when the calcination temperature is below 600°C. The graphical template is burnt out during calcination to leave a hole in the spherical 8%B-TiO2. The BET surface area of the materials declines from 53.2 m2/g at 400°C to 10.6 m2/g at 700°C. High-temperature thermal treatment results in the small surface area and large pore size. The activity of the 8%B-TiO2 materials was studied on adsorption and photocatalytic degradation of RBR X-3B dye. The 8%B-TiO2 sample prepared at 600°C has the maximum activity on RBR X-3B degradation. After five cycles, decoloration efficiency on the 8%B-TiO2 decreases from 100% in the first cycle to 80% in the fifth cycle. Conclusion: Photocatalytic activity of the hollow spherical material depends on calcination temperature with the optimum activity on the sample obtained at 600°C. The hollow spherical 8%B-TiO2 has satisfactory performance for recycling. Photocatalytic degradation of RBR X-3B can be proven by the UV-Vis spectra during the degradation process.

Hydrothermal Synthesis of Nanorods/Nanoparticles TiO2 for Photocatalytic Activity and Dye-sensitized Solar Cell Applications

2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa
Keyword(s):  
Photocatalytic Activity ◽  
Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Energy Conversion Efficiency ◽  
Bet Surface Area ◽  
Average Pore ◽  
Dye Sensitized ◽  
Prepared Material ◽  
20 Nm

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.

Synthesis and Characterizations of Titanium Tungstophosphate Nanoparticles for Heavy Metal Ions Removal

2016 ◽  
Vol 257 ◽  
pp. 187-192 ◽  
Author(s):  
Mohamed Ali Ghanem ◽  
Nezar H. Khdary ◽  
Abdullah M. Almayouf ◽  
Mabrook A. Salah
Keyword(s):  
Metal Ions ◽  
Surface Area ◽  
Self Assembly ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Ionic Exchange ◽  
Characteristic Structure ◽  
X Ray ◽  
Heavy Metal Ions Removal ◽  
Metal Ions Removal

Ionic exchange of multi-components titanium tungstophosphate nanoparticles (TiWP-NPs) were prepared using sol-gel reaction of titanium isoperoxide and tungestophosphoric acid (TPA) in presence of CTAB surfactant. The X-ray, BET and TEM characterizations showed that the nanoparticles exhibit the characteristic structure of titanium tungstophosphate and a BET surface area of 74 ± 3 m2/g was achieved. The TPA has shown an effect on the self-assembly process and maintains the TPA content to minimum would be beneficial for obtaining higher surface area of TiWP nanoparticles. Metal ions adsorption of Cu(II), Pb(II) or Cd(II) using the resulting titanium tungstophosphate nanparticles materials is investigated and up to 95% removal percentage was achieved. Using this method, nanoparticles of ionic exchange titanium tungstophosphate can be synthesized in the form of powder and amenable to mass production.

scholarly journals Interconnected Micro, Meso, and Macro Porous Activated Carbon from Bacterial Nanocellulose for Superior Adsorption Properties and Effective Catalytic Performance

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4063
Author(s):  
Arnon Khamkeaw ◽  
Tatdanai Asavamongkolkul ◽  
Tianpichet Perngyai ◽  
Bunjerd Jongsomjit ◽  
Muenduen Phisalaphong
Keyword(s):  
Activated Carbon ◽  
Reaction Temperature ◽  
Mass Transfer Rate ◽  
Catalyst Support ◽  
Catalytic Performance ◽  
Adsorption Properties ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Bacterial Nanocellulose ◽  
Effective Performance

The porous carbon (bacterial cellulose (BC)-activated carbon (AC)(BA)) prepared via two-step activation of bacterial nanocellulose by treatments with potassium hydroxide (KOH) and then phosphoric acid (H3PO4) solutions showed superior adsorption properties and effective performance as catalyst support. BC-AC(BA) had an open and interconnected multi-porous structure, consisting of micropores (0.23 cm3/g), mesopores (0.26 cm3/g), and macropores (4.40 cm3/g). The BET surface area and porosity were 833 m2/g and 91.2%, respectively. The methylene blue adsorption test demonstrated that BC-AC(BA) was superior in its mass transfer rate and adsorption capacities. Moreover, BC-AC(BA) modified by H3PO4 treatment showed a significant enhancement of catalytic performance for dehydration of ethanol. At the reaction temperature of 250–400 °C, 30P/BC-AC(BA) gave ethanol conversion at 88.4–100%, with ethylene selectivity of 82.6–100%, whereas, high selectivity for diethyl ether (DEE) at 75.2%, at ethanol conversion of 60.1%, was obtained at the reaction temperature of 200 °C.

scholarly journals Catalytic Soot Oxidation Activity of NiO–CeO2 Catalysts Prepared by a Coprecipitation Method: Influence of the Preparation pH on the Catalytic Performance

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3436 ◽  
Author(s):  
Amar Bendieb Aberkane ◽  
María Pilar Yeste ◽  
Djazi Fayçal ◽  
Daniel Goma ◽  
Miguel Ángel Cauqui
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Mixed Oxide ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Coprecipitation Method ◽  
Bet Surface Area ◽  
Mixed Oxide Catalysts ◽  
Ph Values ◽  
Tight Contact

A series of NiO–CeO2 mixed oxide catalysts have been synthesized by a modified coprecipitation method at three different pH values (pH = 8, 9, and 10). The NiO–CeO2 mixed oxide samples were characterized by TGA, XRD, inductively coupled plasma atomic emission spectroscopy (ICP-AES), FTIR, Brunauer–Emmett–Teller (BET) surface area, H2 temperature-programmed reduction (H2-TPR), and electron microscopy (high-angle annular dark-field transmission electron microscopy/energy-dispersive X-ray spectroscopy (HAADF-TEM/EDS)). The catalytic activities of the samples for soot oxidation were investigated under loose and tight contact conditions. The catalysts exhibited a high BET surface area with average crystal sizes that varied with the pH values. Electron microscopy results showed the formation of small crystallites (~5 nm) of CeO2 supported on large plate-shaped particles of NiO (~20 nm thick). XRD showed that a proportion of the Ni2+ was incorporated into the ceria network, and it appeared that the amount on Ni2+ that replaced Ce4+ was higher when the synthesis of the mixed oxides was carried out at a lower pH. Among the synthesized catalysts, Ni-Ce-8 (pH = 8) exhibited the best catalytic performance.

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