scholarly journals Niobium Modification of Au/CeO2 for Enhanced Catalytic Performance over Benzene Combustion

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 189
Author(s):  
Zhe Liu ◽  
Xiaolan Zhang ◽  
Ting Cai ◽  
Jing Yuan ◽  
Kunfeng Zhao ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Area ◽  
Performance Improvement ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Initial Activity ◽  
Support Interaction ◽  
Temperature Performance ◽  
And Performance ◽  
Ceo2 Lattice

A novel Au/Nb-CeO2 was obtained by loading Au to Nb-modified CeO2 adopting a thermal decomposition method. The modification effect of Nb on the physicochemical properties and performance of Au/CeO2 for benzene combustion was systematically clarified. The incorporated Nb species are found to be present in the two forms of highly-dispersed state and bulk NbOx into CeO2 lattice in the obtained Au/Nb-CeO2 catalyst. They greatly enlarged the BET surface area, improved the redox property, and strengthened the Au–support interaction. The addition of Nb also promotes catalytic performance of Au/CeO2, especially high-temperature performance: T90% decreases by ca. 40 °C and Au/Nb-CeO2 exhibits superior stability to Au/CeO2 at 230 °C. The slightly improved Au dispersion and redox properties resulted in the small increase on initial activity of Au/Nb-CeO2, but the large BET surface area and the strong Au–support interaction greatly promoted the high-temperature performance improvement of Au/Nb-CeO2 for benzene combustion reaction.

Surface area and microstructure of microwave activated crumb rubber modifier and its influence on high temperature properties of crumb rubber modifier binders

2020 ◽  
Vol 10 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Bo Li ◽  
Xuwei Zhu ◽  
Xingjun Zhang ◽  
Xiaolong Yang ◽  
Xiuli Su
Keyword(s):  
High Temperature ◽  
Surface Area ◽  
Gas Adsorption ◽  
Treatment Time ◽  
Particle Surface ◽  
Microwave Treatment ◽  
Crumb Rubber ◽  
Adsorption Method ◽  
Temperature Performance ◽  
Mechanism Of Interaction

Crumb rubber pretreatment by microwave before blending with an asphalt matrix can address and improve the modification problem of of crumb rubber modifier (CRM) asphalt plant. In this research, the surface area and microstructure of microwave activated CRM and high-temperature performance of CRM asphalt were investigated to characterize the mechanism of interaction between activated CRM blends added and base asphalt. The surface area and microstructure of CRM were measured by gas adsorption method and the scanning electron microscopy (SEM) respectively when CRM was activated using microwave treatment time (30 s, 60 s, 90 s, 120 s and 150 s). The complex shear modulus (G*) and the phase angle (δ) of the CRM asphalt were measured by Dynamic Shear Rheometer (DSR) test. The results indicated that microwave treatment produced more porous structure and agglomeration phenomenon than control one for a given activated time of CRM. The flocculent structure was the most obvious one and agglomeration phenomenon was the most significant one for the particle surface microwave activated 90 s. The δ decreased and G* increased as CRM blends activated time increased before a certain time using the same frequency of microwave treatment. The G*/sinδ of CRM blends was the maximum when CRM activated for 90 s using microwave treatment. Both surface area and microstructure of the CRM influenced the high-temperature performance of CRM binders.

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.

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.

Methanol Conversion to Propylene over Mo-HZSM-5 Zeolite

2013 ◽  
Vol 834-836 ◽  
pp. 476-480
Author(s):  
Hai Rong Zhang ◽  
Hong Yan Liu ◽  
Yu Jiang ◽  
Xiao Hua Chang ◽  
Kai Yuan ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Al Content ◽  
Strong Acidity

A series of Mo-ZSM-5 zeolites have been synthesized by in site hydrothermal method and their catalytic performance for methanol conversion to propylene was tested in a fixed bed reaction at WHSV=4 h-1, pressure of 1 atm, and MeOH/H2O (mol) ratio of 1. The effect of Mo and Al content on the structure and acidity of Mo-ZSM-5 zeolites were characterized by nitrogen adsorption and NH3-TPD. The results showed that Mo incorporation gradually decreased the BET surface area and weaken the strong acidity on the surface of the zeolites. At 470 °C, the maximum selectivity of propylene and the P/E (Propylene to Ethane) ratio were achieved 45.04 % and 7.30, which were higher than those over Mo free HZSM-5 by 4.12% and 3.47, respectively. Mo-ZSM-5 zeolites are promising catalysts for methanol conversion to propylene with a high P/E.

Mix Design and Performance Research on Asphalt Mixture of SUP-20 with Lucobit

2015 ◽  
Vol 713-715 ◽  
pp. 2765-2768
Author(s):  
Ye Mao Zhang ◽  
Kun Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Asphalt Mixture ◽  
Performance Comparison ◽  
Mix Design ◽  
Water Stability ◽  
Stability Performance ◽  
Temperature Performance ◽  
And Performance ◽  
Performance Research

To research the grading applicability of Lucobit modifier and make it adapt to China's basic national conditions very well, the gradations of SUP-20 was selected to research mix design and pavement performance in the text. First, the mix design of SUP-20 without Lucobit is researched. Then the performance of SUP-20 is verified including the high temperature, low temperature and water stability performance of common asphalt mixture. At last the performance comparison between SUP-20 asphalt mixture with 7% Lucobit and without is carried out. Results show that the performance of SUP-20 asphalt mixture with 7% Lucobit and without can all meet the requirement. Compared with the performance of SUP-20 asphalt mixture without Lucobit, the low temperature and water stability performance with Lucobit have a little improvement and the high temperature performance improves a lot. So Lucobit modifier can greatly improve the high temperature performance of SUP-20 asphalt mixture.

Influence of Catalysts with Different Templates on Direct Decomposition of NO in Cement Kiln Exhaust

2018 ◽  
Vol 913 ◽  
pp. 948-953
Author(s):  
Yan Ling Gan ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Xiao Yu Ma ◽  
Ya Li Wang
Keyword(s):  
Surface Area ◽  
Decomposition Rate ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Direct Decomposition ◽  
No Decomposition ◽  
Bet Surface Area ◽  
Cement Kiln ◽  
Porous Catalyst ◽  
Decomposition Of No

The influence of catalysts with different templates on direct decomposition of NO in cement kiln exhaust was studied in this paper. The NO direct decomposition rate of porous catalyst materials with different templates was determined by infrared spectrometer. And pore structure and the microstructure of the catalysts were characterized by BET surface area, nitrogen adsorption-desorption. The results show that the catalytic performance of porous catalyst without any template is better than catalysts with other templates at low temperature. When the temperature reached 550 °C, NO decomposition rate of porous catalyst with CTAB could reach to more than 80%. And meanwhile, the catalysts with organic template reagent have higher BET surface area than those with inorganic template agent. With the increasing of the reaction time, the NO decomposition rate decreases. After reaction for 3 hours, the decomposition rate decreases from 80% to 40%.

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%.

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