scholarly journals The formation of silica, alumina and zirconia supported high surface area monometallic and bimetallic catalysts. Progress report

1993 ◽  
Author(s):  
R.D. Gonzalez
2008 ◽  
Vol 368-372 ◽  
pp. 1712-1715
Author(s):  
Hong Yan Xu ◽  
Xiao Jun Bao ◽  
Ting Hai Wang ◽  
Yong Gang Wang

The silica-alumina-pillared montmorillonite materials (SiAl-MMT) were developed by a novel method, which combined several techniques such as ion-exchange, intercalation and surfactant modification. The morphology, composite structure and pore properties of such composite materials, were investigated by X-ray powder diffraction (XRD), Scanning Electronic Microscopy (SEM), Fourier-transform infra-red (FTIR) spectra, as well as Nitrogen Adsorption-Desorption Isotherms. The layer structure of the prepared materials retained and their pore structures were found to be slit-shaped pores located between plate-like particles. The prepared SiAl-MMT materials had a BJH pore volume of 0.63cm3 g-1, a remarkably high BET specific surface area beyond 1000 m2 g-1, and a narrow pore size distribution in the mesoporous region 3.5-4 nm after thermal treatment at 600 °C.


Author(s):  
A. Sachdev ◽  
J. Schwank

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.


Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>


Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  

High surface area FeP nanosheets on a carbon cloth were prepared by gas phase phosphidation of electroplated FeOOH, which exhibit exceptionally high catalytic efficiency and stability for hydrogen generation.


Author(s):  
Sisir Maity ◽  
Dheeraj Kumar Singh ◽  
Divya Bhutani ◽  
Suchitra Prasad ◽  
Umesh V. Waghmare ◽  
...  

MethodsX ◽  
2021 ◽  
pp. 101464
Author(s):  
Yichen Wu ◽  
Nan Zhang ◽  
Charles-François de Lannoy

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