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Investigation of the energetics of the decomposition of azomethane on Pd(111): The UBI-QEP approach
, Article Surface Review and Letters ; Volume 10, Issue 6 , 2003 , Pages 895-901 ; 0218625X (ISSN) ; Gobal, F ; Sharif University of Technology
2003
Abstract
The method of unity bond index-quadratic exponential potential (UBI-QEP) is employed to derive the energetic parameters associated with the steps of the pathway which we propose for the catalytic decomposition of azomethane on the Pd(111) surface. According to the energy calculations, azomethane adsorbs molecularly in trans-configuration and then decomposes to CH3N with no activation energy. The reaction continues by tilting and dehydrogenation to the products (H2 and HCN). The calculated activation energies at various surface coverages perfectly account for the variation of relative yields of H2 and HCN with changing of the coverage of azomethane. According to the calculations, desorption...
Simulation of Surface Chemical Reactions in Bosch Process for a Polymer Film and Investigation of Etching Quality
, M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Saeed (Supervisor)
Abstract
Deep reactive ion etching is one of the most used techniques for manufacturing micro-structures. The most popular silicon DRIE technique is Bosch process. Ability to manufacture high aspect ratio features made Bosch process the main technique for developing micro-electromechanical devices. Dry etching is a combination of physical and chemical processes. The chemical processes play a very important role due to their speed of material removing and also due to their high selectivity. Also chemical processes are responsible for development of passive resist layer on the surface. On the other hand, if not controlled properly it can reduce anisotropy, resulting in a low quality etch. In this...
Review - Towards the two-dimensional hexagonal boron nitride (2D h-BN) electrochemical sensing platforms
, Article Journal of the Electrochemical Society ; Volume 167, Issue 12 , 2020 ; Khalaj, M ; Alem, S. A. A ; Pakdel, A ; Willander, M ; Hatamie, A ; Simchi, A ; Sharif University of Technology
IOP Publishing Ltd
2020
Abstract
Electrochemical sensing performance of two-dimensional hexagonal boron nitride (2D h-BN) has traditionally been suppressed by their intrinsic electrical insulation and deficient electron transportation mechanism. However, the excellent electrocatalytic activity, high specific surface area, N- and B-active edges, structural defects, adjustable band gap through interaction with other nanomaterials, and chemical functionalization, makes 2D h-BN ideal for many sensing applications. Therefore, finding a pathway to modulate the electronic properties of 2D h-BN while the intrinsic characteristics are well preserved, will evolve a new generation of highly sensitive and selective electrochemical...
Kinetics of platinum extraction from spent reforming catalysts in aqua-regia solutions
, Article Hydrometallurgy ; Volume 95, Issue 3-4 , 2009 , Pages 247-253 ; 0304386X (ISSN) ; Khosravian Gh., H ; Mortaheb, H. R ; Sharif University of Technology
2009
Abstract
Platinum content of two commercial spent reforming catalysts were extracted in aqua-regia solutions under atmospheric pressure and at temperatures up to 100 °C. Three factors, including presence of coke, catalyst particle size, and impeller agitation speed were first tested to study the relative importance of mass-transfer resistances during Pt extraction reaction. Catalyst particle sizes < 100 μm and agitation speeds > 700 rpm eliminated the internal and external mass-transfer resistances, respectively. The effect of other factors, including HNO3-to-HCl volume ratio, liquid-to-solid mass ratio, and the reaction temperature on the extraction rate of platinum were then examined. Pt extraction...