The specific surface area and catalytic properties of the calcination products of δ-FeOOD

1979 ◽  
Vol 110 (1) ◽  
pp. 27-33 ◽  
Author(s):  
F. Domka ◽  
A. Basińska
2021 ◽  
Vol 10 (3) ◽  
pp. 01-08
Author(s):  
Khalid Ouzaouit ◽  
Abdelhay Aboulaich

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.


2021 ◽  
Vol 1 (4) ◽  
pp. 1-1
Author(s):  
Ludmila Velichkina ◽  
◽  
Yakov Barbashin ◽  
Alexander Vosmerikov ◽  
◽  
...  

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.


2011 ◽  
Vol 287-290 ◽  
pp. 1718-1722 ◽  
Author(s):  
Jian Xin Cai ◽  
Yi Hao Lv ◽  
Rong Bin Zhang ◽  
Lai Tao Luo

Ce0.7M0.3CoOx catalysts were prepared by polyatomic alcohol method. The crystal structure, reduction and adsorption properties, and specific surface were investigated by XRD, TPR, TPD, BET, respectively. The results show that catalysts doped with different oxides can make great effects on the catalytic properties of the Co3O4-CeO2. The interaction between doping oxides (SrO, NiO, La2O3, ZrO2, Nd2O3) and Co3O4-CeO2 is contributed to the change of the reduction and adsorption performance, and specific surface area of the catalysts. SrO doping can promote CeO2 reduction, CO adsorption and low-temperature oxidative activity of the catalysts. The conversion of CO can reach 100% over the Ce0.7Sr0.3CoOx at 120 °C temperature.


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