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%.

Effect of Silica-Alumina Ratio of Catalysts on NO Decomposition Rate in Cement Kiln Exhaust

2020 ◽  
Vol 993 ◽  
pp. 1450-1455
Author(s):  
Yan Ling Gan ◽  
Su Ping Cui ◽  
Xiao Yu Ma ◽  
Ya Li Wang
Keyword(s):  
Surface Area ◽  
Decomposition Rate ◽  
Catalytic Decomposition ◽  
Nitrogen Adsorption ◽  
No Decomposition ◽  
Bet Surface Area ◽  
Cement Kiln ◽  
Average Pore ◽  
Silica Alumina ◽  
Silica Alumina Ratio

In order to deal with the pollution of NO in cement kiln exhaust, the study of NO catalytic decomposition catalyst obtained much more attention. The effect of silica-alumina ratio on NO decomposition rate in cement kiln without other reductant was studied. The NO decomposition rate of catalysts with different silica-alumina ratio was determined by infrared spectrometer. And pore structures and the microstructure of the catalyst were characterized separately by BET surface area, nitrogen adsorption-desorption and XRD. The results show that silica-alumina ratio of catalyst was preferred to be 50 with the best NO decomposition rate when the temperature was below 300 °C. The catalyst with silica-alumina ratio of 60 has the higher catalytic activity when the temperature was higher than 300 °C, and the decomposition rate achieved 70% at 600 °C. XRD results shows the crystallinity of catalysts increased as the silica-alumina ratio increased. BET surface area and the cumulative pore volume of catalysts gradually increased, and the average pore diameter gradually reduced with the increase of silica-alumina ratio.

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.

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.

An Experimental Analysis of Lactic Acid Esterification Process Using Langmuir-Hinshelwood Model

2017 ◽  
Vol 733 ◽  
pp. 36-41
Author(s):  
Edidiong Okon ◽  
Habiba Shehu ◽  
Edward Gobina
Keyword(s):  
Lactic Acid ◽  
Cation Exchange ◽  
Pore Size ◽  
Surface Area ◽  
Cation Exchange Resin ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Gas Chromatography Mass Spectrometry ◽  
Type Iv ◽  
Exchange Resins

In this study, esterification of lactic acid and ethanol to produce ethyl lactate using different cation-exchange resin catalysts was performed at 100 °C. The catalysts used for the esterification process were amberlyst 16 and dowex 50W8x cation-exchange resins. Two simplified mechanisms based on Langmuir-Hinshelwood model were employed to describe the components that adsorbed most on the surface of the catalysts. Fourier Transform Infrared (Nicolet iS10 FTIR) was employed to verify the rationality of the mechanisms. FTIR of the esterification product reflected C=O, H=O and C=C bonds on the spectra confirming water and ethanol as the most adsorbed components. The kinetic study of the retention time and the peak areas of the esterification produced with the different catalysts were compared using an autosampler gas chromatography/mass spectrometry (autosampler GC-MS). The chromatogram of the esterification product catalysed by amberlyst 16 showed a faster elution at 1.503 mins with the peak area of 1229816403 m2 in contrast to the dowex 50W8x. The BET surface area and BJH pore size distribution of the resin catalysts were determined using liquid nitrogen adsorption (Quantachrome, 2013) at 77 K. The BET surface area results of amberlyst 16 resin catalysts was found to be 1.659m2/g compared to 0.1m2/g for the dowex 50W8x. The BJH results of the catalysts exhibited a type IV isotherm with hysteresis confirming that the materials were mesoporous with pore size in the region of 2 – 50 nm.

scholarly journals Preparation of Cu-Al/SiO2 Porous Material and Its Effect on NO Decomposition in a Cement Kiln

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Yanling Gan ◽  
Suping Cui ◽  
Xiaoyu Ma ◽  
Hongxia Guo ◽  
Yali Wang
Keyword(s):  
Porous Material ◽  
Decomposition Rate ◽  
Active Phase ◽  
Mesoporous Structure ◽  
Atmospheric Environment ◽  
No Decomposition ◽  
Material Structure ◽  
Cement Kiln ◽  
X Ray Diffraction ◽  
Infrared Spectrometer

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 °C, and NO decomposition rate could approach 100% at high temperatures above 750 °C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet–visible spectrophotometry (UV–Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material.

scholarly journals Comparison of Nitrogen Adsorption and Mercury Penetration Results. Pore Size Distributions for a Series of Mo-A12O3 Catalysis with Increasing MoO3 Content

1987 ◽  
Vol 4 (1-2) ◽  
pp. 87-104 ◽  
Author(s):  
Bruce D Adkins ◽  
Jill B. Heink ◽  
Burtron H. Davis
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
Three Dimensional ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Size Distributions ◽  
Electron Microscopic ◽  
Pore Size Distributions ◽  
Electron Microscopic Data ◽  
Penetration Data

Scanning electron microscopic data, X-ray diffraction patterns and porosity measurements are consistent with a structure for an Mo-A12O3 catalyst series containing a single surface layer of Mo up to the point where the Mo loadings exceed the amount required for a monolayer. For greater Mo loadings than required for a monolayer, three dimensional orthorhombic MoO3 is also present. The cumulative pore volume, on an alumina basis, does not appear to be significantly altered by MoO3 loadings up to about 15 wt.%. The BET surface area, on an alumina basis, remains constant with Mo loading. However, the apparent surface area calculated from mercury penetration data decreases with Mo loading. For these materials with cylindrical pores, the Broekhoff-deBoer model for the calculation of pore size distributions produced closer agreement to the mercury penetration pore size distribution. This is in contrast to materials composed of nonporous spheres where the Broekhoff-deBoer model provided poorer agreement to mercury penetration results than either the Cohan or a packed sphere model. The results show that, within a factor of two the pore size distributions calculated from nitrogen adsorption and mercury penetration data are comparable.

scholarly journals A Review on the Catalytic Decomposition of NO by Perovskite-Type Oxides

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 622
Author(s):  
Qiuwan Shen ◽  
Shuangshuang Dong ◽  
Shian Li ◽  
Guogang Yang ◽  
Xinxiang Pan
Keyword(s):  
Mixed Oxides ◽  
Low Cost ◽  
Influence Factors ◽  
Catalytic Decomposition ◽  
Catalytic Performance ◽  
No Decomposition ◽  
Reaction Conditions ◽  
A Site ◽  
Perovskite Type ◽  
Decomposition Of No

Direct catalytic decomposition of NO has the advantages of being a simple process, producing no secondary pollution, and being good for the economy, which has attracted extensive research in recent years. Perovskite-type mixed oxides, with an ABO3 or A2BO4 structure, are promising materials as catalysts for NO decomposition due to their low cost, high thermal stability, and, of course, their good catalytic performances. In this review, the influence factors, such as A-site substitution, B-site substitution and reaction conditions on the catalytic performance of catalysts have been expounded. The reaction mechanisms of direct NO decomposition are also discussed. Finally, major conclusions are drawn and some research challenges are highlighted.

scholarly journals The Role of the Aluminum Source on the Physicochemical Properties of γ-AlOOH Nanoparticles

2020 ◽  
Vol 39 (1) ◽  
pp. 89
Author(s):  
Rafael Romero Toledo ◽  
Luis M. Anaya Esparza ◽  
J. Merced Martínez Rosales
Keyword(s):  
Electron Microscopy ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
X Ray ◽  
Aluminum Salts ◽  
Adsorption Desorption

The effect on the physicochemical properties of aluminum salts on the synthesis of γ-AlOOH nanostructures has been investigated in detail using a hydrolysis-precipitation method. X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), were used to characterize the synthesized samples. The specific surface area, pore size distribution and pore diameter of the different γ-AlOOH structures were discussed by the N2 adsorption-desorption analysis. According to the results of the nanostructure, characterization revealed that for synthesized γ-AlOOH nanostructures from AlCl3 and Al(NO3)3, obvious XRD peaks corresponding to the bayerite phase are found indicating an impure γ-AlOOH phase. Furthermore, the nitrogen adsorption-desorption analysis indicated that the obtained γ-AlOOH nanoparticles from Al2(SO4)3 of technical grade (95.0 % of purity) and low cost, possess a high BET surface area of approximately 350 m2/g, compared to the obtained nanostructures from aluminum sources reactive grade, which was attributed to the presence of Mg (0.9 wt.%) in its nanostructure.

Morphological Control Synthesis and Characterization of Hydroxyapatite with Star-Shaped

2010 ◽  
Vol 152-153 ◽  
pp. 1603-1606
Author(s):  
Ya Jie Guo ◽  
Yu Ran Wang ◽  
Guang Jian Wang ◽  
Zhen Xing Yang ◽  
Wen Wen Ji
Keyword(s):  
Ionic Liquid ◽  
Surface Area ◽  
Self Assembly ◽  
Nitrogen Adsorption ◽  
High Specific Surface Area ◽  
Bet Surface Area ◽  
Control Synthesis ◽  
X Ray Diffraction ◽  
One Step

The aim of the present work was to study the feasibility of wet synthesizing hydroxyapatite (HAP) with star-like and high specific surface area. HAP was synthesized by one-step self-assembly process in ionic liquid media under microwave irradiation, and treated at 300, 600, 900 , respectively. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis revealed that HAP was pure crystal phase. Nitrogen adsorption and desorption isotherms (NADI) with a characteristic hysteresis loop further confirmed the existence of uniform micropores or channels of HAP. The BET surface area, pore volume, and pore size distribution were calculated to be 324m2g-1, 0.39cm3g-1, and 3.28 nm, respectively. Scanning electron microscopy (SEM) results indicated that the HAP was of star-shaped morphology. The formation of HAP could be explained by functional ionic liquid as structure-directing template. Well-ordered mesostructure of HAP with star-like might be therefore used as a potential biomaterial for preparation of bone implant materials.

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