Effect of lanthanide promotion on catalytic performance of sol–gel Ni/Al2O3 catalysts in steam reforming of propane

2005 ◽  
Vol 241 (1-2) ◽  
pp. 133-146 ◽  
Author(s):  
Sittichai Natesakhawat ◽  
Okan Oktar ◽  
Umit S. Ozkan
Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 19
Author(s):  
Alexandra Lytkina-Payen ◽  
Natalya Tabachkova ◽  
Andrey Yaroslavtsev

Methanol steam reforming (MSR) is considered an effective method for hydrogen storage and to generate high-quality hydrogen for fuel cells. In this work, a comprehensive investigation of the methanol steam reforming process using a bimetallic Pt–Rh and Cu–Ni based on different oxide supports is presented. Highly dispersed titania and zirconia doped with indium and niobium ions were synthesized by sol–gel method. The effect of the nature and quantity of the dopant cation (In, Nb) on the catalytic performance of titania supported metal catalysts was investigated. The conclusions obtained show a significant effect of both the metal alloy and the oxide support nature on the activity and selectivity of the methanol steam reforming process. Pt–Rh alloy catalyst shows higher hydrogen yield, but its selectivity in the MSR process is lower than for the catalysts containing the Cu0.8-Ni0.2 alloy. Heterovalent indium doping of titania leads to the catalytic activity increase. It was suggested that this is due to the defects formation in the oxygen TiO2 sublattice. On the contrary, the use of niobium oxide as a dopant decreases the catalyst activity in the methanol steam reforming process but leads to the selectivity increase in the studied process.


2005 ◽  
Vol 885 ◽  
Author(s):  
Krithi Shetty ◽  
Shihuai Zhao ◽  
Wei Cao ◽  
Naidu V. Seetala ◽  
Debasish Kuila

ABSTRACTThe goal of this research is to investigate the activities of a non-noble nano-catalyst (Ni/SiO2) using Si-microreactors for steam reforming of methanol to produce hydrogen for fuel cells. The supported catalyst was synthesized by sol-gel method using Ni (II) salts and Si(C2H5O)4 as starting materials. EDX results indicate that the actual loading of Ni (5-6%) is lower than the intended loading of 12 %. The specific surface area of the silica sol-gel encapsulated Ni nano-catalyst is 452 m2/g with an average pore size of ∼ 3 nm. Steam reforming reactions have been carried out in a microreactor with 50 µm channels in the temperature range of 180-240 °C and atmospheric pressure. Results show 53% conversion of methanol with a selectivity of 74 % to hydrogen at 5 l/min and 200 °C. The magnetic properties of the catalysts were performed using a Vibrating Sample Magnetometer (VSM) to study the activity of the catalysts before and after the steam reforming reactions. The VSM results indicate much higher activity in the microreactor compared to macro-reactor and Ni forms non-ferromagnetic species faster in the microreactor.


Fuel ◽  
2013 ◽  
Vol 103 ◽  
pp. 122-129 ◽  
Author(s):  
Mitsuru Koike ◽  
Chiaki Ishikawa ◽  
Dalin Li ◽  
Lei Wang ◽  
Yoshinao Nakagawa ◽  
...  

2021 ◽  
Vol 13 (3) ◽  
pp. 371-380
Author(s):  
Yongjun Wu ◽  
Nina Xie ◽  
Lu Yu

A novel Ag–Si–TiO2 composite was prepared via sol–gel method for removing residual formaldehyde in shiitake mushroom. The structure of Ag–Si–TiO2 composite was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. Ultraviolet-visible absorption spectroscopy (UV-Vis) and N2 adsorption-desorption tests showed that Ag and Si co-doped decreased the band gap, the Brunauer-Emmett-Teller (BET) specific surface area of the samples increased and the recombination probability of electron-hole pairs (e--h+) reduced. Effect on removal rate of formaldehyde with different Ag-Si co-doped content, formaldehyde concentration and solution pH were investigated, and the results showed that 6.0 wt%Ag-3.0 wt%Si-TiO2 samples had an optimum catalytic performance, and the degradation efficiency reached 96.6% after 40 W 365 nm UV lamp irradiation for 360 min. The kinetics of formaldehyde degradation by Ag–Si–TiO2 composite photocatalyst could be described by Langmuir-Hinshelwood first-order kinetic model.


2014 ◽  
Vol 617 ◽  
pp. 170-173
Author(s):  
Tetsuo Umegaki ◽  
Shunsuke Imamura ◽  
Naoki Toyama ◽  
Qiang Xu ◽  
Yoshiyuki Kojima

The present study reports a facile and effective approach for fabrication of hollow silica-alumina composite spheres. In this approach, silica-alumina composite walls were coated on polystyrene template by the sol-gel method using L(+)-arginine as a promoter for the reaction followed by calcination procedure. Using L(+)-arginine as a promoter of coating process, homogeneous hollow silica-alumina composite spheres are obtained and the wall thickness is larger than that of the hollow spheres prepared with ammonia. The hollow spheres shows high activity for hydrolytic dehydrogenation of ammonia borane compared with spherical silica-alumina composite particles without hollow structure, the hollow spheres prepared with ammonia, and conventional H-BEA zeolite. The results indicate that hollow structure plays important role to show high activity.


2008 ◽  
Vol 8 (1 & 2) ◽  
pp. 19
Author(s):  
Anton Purnomo ◽  
Susan Gellardo ◽  
Leonila Abella ◽  
Hirofumi Hinode ◽  
Chris Salim

Catalytic performance and characterization of Ni/CeO2/ZrO2 and commercial catalyst from Indonesia were investigated in steam reforming of methane. Ni/CeO2/ZrO2 catalyst was prepared using co-impregnation of cerium nitrate and nickel nitrate onto zirconia support material. BET, SEM, EDS, XRD, TPD, TG, and ICP analyses were employed for the characterization of the catalysts. Remarkable catalytic performance of Ni/CeO2/ZrO2 catalyst at 600oC operating temperature and atmospheric pressure of about 74.9% methane conversion was obtained compared to 55.9% using the commercial catalyst. In addition, the presence of cerium in Ni/CeO2/ZrO2 was effective in improving the stability and resistance to coke formation. Less carbon formation was confirmed from the thermo-gravimetric analysis. These results showed that the prepared catalyst is promising in the industrial application which can be used at lower operation temperature for energy saving.


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