Fickian Spillover Models Validation and Parameter Estimation

Date

2015-08-30

Author

Dheerendra, Singh
Üner, Necip Berker
Üner, Deniz

Metadata

Show full item record

Item Usage Stats

129
views

0
downloads

The phenomenon and mechanism of spillover process is being discussed for the last two decades and accepted as an important step in understanding the dynamics of catalysts and improving their performance. Although the characterization and the theory of surface diffusion on perfect crystals has been treated to a good extent, the effect of spillover and surface diffusion on the performance of regularly synthesized supported catalysts is still vague. In this study, H2 chemisorption involving sequential adsorption-desorption experiments was done on Pt/Al2O3 catalysts. The model of Kramer and Andre (J. Catal., vol. 58, pp. 287–295, 1979) is used to predict both adsorption and desorption rates from the catalysts. This Fickian description gives a good fit for both stages. Such a model is expected to predict amounts on the surface diffusion-influenced synthesis via new nanostructured catalysts. The model will be used to make predictions of hydrogenation reactions.

URI

http://www.europacat2015.com/
https://hdl.handle.net/11511/85631

Conference Name

12th EUROPEAN CONGRESS ON CATALYSIS (30 Ağustos - 04 Eylül 2015)

Collections

Department of Chemical Engineering, Conference / Seminar

Suggestions

OpenMETU
Core

Stochastic surplus processes with VaR AND CVaR simulations in actuarial applications Şimşek, Meral; Uğur, Ömür; Kestel, Sevtap Ayşe; Department of Actuarial Sciences (2016) The theory of ruin is a substantial study for those who are interested in ﬁnancial survival probability based on the patterns imposed by the surplus process, which determines the insurer’s capital balance at a given time. In other words, ﬂuctuations in aggregate claims as well as premiums in such processes can be secured by a certain capital. In this study, we simulate various surplus processes under different claim sizedistribution assumptions and extend the analyses by adding perturbation of a Brownian mo...
Phase transition of chemically synthesized FePt nanoparticles under high pressure ŞİMŞEK, TELEM; Karci, Ozgur; ÖZCAN, ŞADAN (The Scientific and Technological Research Council of Turkey, 2018-01-01) We present the results of a study related to phase transformation of chemically synthesized FePt nanoparticles under high pressure from face-centered cubic into face-centered tetragonal structure. As-synthesized nanoparticles are around 4.5 nm and show superparamagnetic behavior at 300 K. After annealing under 60 bar pressure of hydrogen at 400 degrees C for 2 h, nanoparticles exhibit strong ferromagnetic behavior with 5391 Oe coercivity. Results show that high-pressure annealing lowers the decomposition te...
Multinucleon transfer in central collisions of U-238+U-238 Ayik, S.; YILMAZ, BÜLENT; YILMAZ TÜZÜN, ÖZGÜL; Umar, A. S.; Turan, Gürsevil (2017-08-14) Quantal diffusion mechanism of nucleon exchange is studied in the central collisions of U-238 + U-238 in the framework of the stochastic mean-field (SMF) approach. For bombarding energies considered in this work, the dinuclear structure is maintained during the collision. Hence, it is possible to describe nucleon exchange as a diffusion process for mass and charge asymmetry. Quantal neutron and proton diffusion coefficients, including memory effects, are extracted from the SMF approach and the primary fragm...
Glycosylated proteins preserved over millennia: N-glycan analysis of Tyrolean Iceman, Scythian Princess and Warrior Özcan Kabasakal, Süreyya; Ro, Grace; Kim, Jae-Han; Bereuter, Thomas L.; Reiter, Christian; Dimapasoc, Lauren; Garrido, Daniel; Mills, David A.; Grimm, Rudolf; Lebrilla, Carlito B.; An, Hyun Joo (2014-05-16) An improved understanding of glycosylation will provide new insights into many biological processes. In the analysis of oligosaccharides from biological samples, a strict regime is typically followed to ensure sample integrity. However, the fate of glycans that have been exposed to environmental conditions over millennia has not yet been investigated. This is also true for understanding the evolution of the glycosylation machinery in humans as well as in any other biological systems. In this study, we exami...
NiMoS/gamma-Al2O3 catalysts: The nature and the aging behavior of active sites in HDN reactions ZHANG, LEE P; Karakaş, Gürkan; OZKAN, UMIT S (Elsevier BV, 1998-09-10) The work presented in this paper is a continuation of our earlier work aimed at acquiring a fundamental understanding of sulfided Ni-Mo/gamma-Al2O3 catalysts in HDN catalysis, A series of temperature-programmed desorption and reduction experiments were performed over in-situ sulfided bare gamma-alumina support, alumina-supported monometallic Ni, Mo, and bimetallic NiMo catalysts. The TPD and TPR results were linked to the active site assignment of Ni- and Mo-associated centers in HDN reactions. Postreaction...

Citation Formats

S. Dheerendra, N. B. Üner, and D. Üner, “Fickian Spillover Models Validation and Parameter Estimation,” presented at the 12th EUROPEAN CONGRESS ON CATALYSIS (30 Ağustos - 04 Eylül 2015), Kazan, Rusya, 2015, Accessed: 00, 2021. [Online]. Available: http://www.europacat2015.com/.