Nd-Doped Barium Cerate Nano-Sized Catalyst Converts CH4 into CO2 at Lower Temperature Compared to Noble Metal-Based Pd/Al2O3 Catalyst

2021 ◽  
Vol 10 (3) ◽  
pp. 01-08
Author(s):  
Khalid Ouzaouit ◽  
Abdelhay Aboulaich
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Properties ◽  
Area Measurement ◽  
Barium Cerate ◽  
In Situ Ftir Spectroscopy ◽  
Lower Temperature ◽  
Doped Barium Cerate ◽  
Al2o3 Catalyst

The present paper describes the synthesis and first application of Nd-doped BaCeO3 nanoparticles as catalyst for the catalytic oxidation of methane (CH4) into CO2. Nd-doped barium cerate BaCeO3 nanoparticles, with the formula BaNdxCe(1-x)O3, have been prepared using a simple sol gel method starting from acetate precursors. The as-prepared nanoparticles have been fully characterized by XRD, TEM, HRTEM and specific surface area measurement. Results confirmed the formation of highly crystallized nano-sized particles with small crystallite size. In-situ FTIR spectroscopy was used to study the catalytic conversion of methane (CH4) into CO2 in the presence of the as-prepared Nd-doped BaCeO3 nanocatalyst. The catalytic properties of such nanocatalysts have been discussed and correlated to Nd-doping rate, crystallite diameter, and specific surface area of the materials. Excellent catalytic properties have been obtained with BaNd0.05Ce0.95O3, such as, superior conversion efficiency, longer catalysis lifetime and lower activation temperature compared to un-doped BaCeO3 catalyst. Interestingly, it was found that BaNd0.05Ce0.95O3 nanocatalyst successfully converts the totality of CH4 present in a mixture of CH4-Air into CO2 at much lower temperature compared to the conventional Pd/Al2O3 catalyst.

scholarly journals Features of obtaining the catalyst for the synthesis of carbon nanotubes

2019 ◽  
Vol 81 (2) ◽  
pp. 261-267 ◽  
Author(s):  
E. A. Burakova ◽  
G. S. Besperstova ◽  
M. A. Neverova ◽  
A. G. Tkachev ◽  
N. V. Orlova ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Decomposition ◽  
Metal Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Nanostructured Materials ◽  
Specific Surface Area ◽  
Oxide System ◽  
Decomposition Stage ◽  
Al2o3 Catalyst

In this paper, the features of obtaining a Co-Mo/Al2O3 catalyst to synthesize carbon nanotubes (CNTs) by thermal decomposition were studied. It was revealed that the duration of the pre-catalyst thermal decomposition stage in the process of developing a metal oxide system has a significant impact on its activity in the synthesis of carbon nanostructured materials by chemical vapor deposition (CVD). It was proved that an effective catalyst for CNTs synthesis can be obtained by through thermal decomposition of the pre – catalyst, without calcination of the metal oxide system. The use of the Co-Mo/Al2O3 catalyst, synthesized in such a way, in the CVD process makes it possible to reduce the cost of synthesized CNTs. Using scanning electron microscopy, it was shown that the size of the grains, and specific surface area of the formed Co-Mo/Al2O3 catalyst depend on the thermal treatment conditions of the pre-catalyst. Under the conditions for the implementation of the pre-catalyst thermal decomposition stage (temperature, volume, duration, etc.), it is possible to contro not only the characteristics of the resulting catalyst (specific surface area, efficiency), but also the characteristics of the CNTs (diameter, degree of defectiveness). In the course of experiments, the optimal modes of implementation of the method for obtaining the Co-Mo/Al2O3 catalyst allowed forming a system with a specific surface area of ~ 108 m2/g. The use of the resulting catalyst in the synthesis of nanostructured materials provides a high specific yield of multi-walled CNTs with a diameter of 8-20 nm and a degree of defectiveness of 0.97.

Alumina aerogel catalysts prepared by two supercritical drying methods used in methane combustion

1995 ◽  
Vol 10 (6) ◽  
pp. 1424-1428 ◽  
Author(s):  
Yasuyuki Mizushima ◽  
Makoto Hori
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Methane Combustion ◽  
Supercritical Drying ◽  
High Specific Surface Area ◽  
The Other ◽  
Drying Methods ◽  
Alumina Aerogel ◽  
Lower Temperature

Palladium-supported alumina aerogels were prepared by two different supercritical drying methods. In one method, an alumina wet gel was dried under supercritical conditions of ethanol in an autoclave. In the other, the aerogel was supercritically dried by extracting ethanol using carbon dioxide in an extractor. The Pd-supported alumina aerogel prepared in the autoclave exhibited a high specific surface area of 112.8 m2/g after firing at 1200 °C for 5 h, while the other had a specific surface area of only 5.2 m2/g due to α-alumina transformation. Their catalytic properties for methane combustion were measured. The Pd-supported alumina aerogel prepared in the autoclave combusts methane perfectly at 50–60 °C lower temperature than the other. Palladium particles on the alumina aerogel prepared in the autoclave contained palladium oxide, while those prepared in the CO2 extractor contained only palladium metal.

scholarly journals Effect of Acid Treatment on the Properties of Zeolite Catalyst for Straight-Run Gasoline Upgrading

2021 ◽  
Vol 1 (4) ◽  
pp. 1-1
Author(s):  
Ludmila Velichkina ◽  
◽  
Yakov Barbashin ◽  
Alexander Vosmerikov ◽  
◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Acid Treatment ◽  
Catalytic Properties ◽  
Fixed Bed ◽  
Acid Sites ◽  
Gasoline Fraction ◽  
Zeolite Catalysts ◽  
Acidic Properties

The objective of this research was to analyze the effect of different concentrations of nitric and hydrochloric acids on the structural, acidic, and catalytic properties of a post-synthetic treated ZSM-5 type zeolite at various temperatures. The properties of zeolite catalysts were determined using different methods, such as the Brunauer-Emmett-Teller (BET) method for specific surface area, temperature-programmed desorption (TPD) of ammonia method for acidic properties, and a flow-through unit with fixed bed catalyst (with upgrading straight-run gasoline fraction of oil) for catalytic activities of initial zeolite and acid-treated samples. The structural and acidic properties of both untreated and treated zeolites were investigated, and the effect of acid treatment on the catalytic properties of the samples in the course of upgrading the straight-run gasoline fraction of oil was determined. The post-synthetic treatment with aqueous nitric acid increased the specific surface area and volume of micropores of ZSM-5 zeolite, while the treatment with aqueous hydrochloric acid led to the formation of mesopores. Acid treatments of zeolite decreased the number of acid sites, mainly due to diminished concentration of low-temperature sites. The yield of liquid products in the conversion of straight-run gasoline fraction of oil, i.e., generation of high-octane gasolines with improved environmental features, was increased using acid-treated zeolites, which was due to the decrease in arene content.

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