Temperature-programmed desorption as a tool to extract quantitative kinetic or energetic information for porous catalysts

Kanervo, Jaana; Keskitalo, Tuomo; Slioor, R. I.; Krause, A.O.I.

doi:10.1016/j.jcat.2005.12.026

Cited by 50 publications

(50 citation statements)

References 21 publications

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“…In the present work, it has been found that about 12% and 6% of o-xylene, on bentonite and silica, respectively, remained adsorbed although the isothermal desorption curve reached zero. This adsorptive behavior suggests the use of the Temperature-Programmed Desorption (TPD) method for determination of desorption energy Ed value, as firstly reported by Cvetanovic, then by several authors [1,9,[40][41][42]. The method is based on measuring the desorption profile with temperature increase, which goes through a maximum and finally back to zero, indicating that the surface is cleared of adsorbate.…”

Section: Application Of the Isosteric Heat Methodsmentioning

confidence: 80%

Non-Calorimetric Determination of the Adsorption Heat of Volatile Organic Compounds under Dynamic Conditions

et al. 2015

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Avoiding strong chemical bonding, as indicated by lower heat of adsorption value, is among the selection criteria for Volatile Organic Compounds adsorbents. In this work, we highlight a non-calorimetric approach to estimating the energy of adsorption and desorption based on measurement of involved amounts, under dynamic conditions, with gaseous Fourier Transform Infrared spectroscopy. The collected data were used for obtaining adsorption heat values through the application of three different methods, namely, isosteric, temperature programmed desorption (TPD), and temperature-programmed adsorption equilibrium (TPAE). The resulting values were compared and discussed with the scope of turning determination of the heat of adsorption with non-calorimetric methods into a relevant decision making tool for designing cost-effective and safe operating of adsorption facilities.

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Section: Application Of the Isosteric Heat Methodsmentioning

confidence: 80%

Non-Calorimetric Determination of the Adsorption Heat of Volatile Organic Compounds under Dynamic Conditions

et al. 2015

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“…The reactor was modeled as a dynamic pseudohomogeneous plug flow reactor, which is applicable as intraparticle mass transfer can be excluded and molar flows have a gradient in the axial direction [22]:…”

Section: Kinetic Modelingmentioning

confidence: 99%

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Viinikainen

Kouva

Lehtonen

et al. 2016

Applied Catalysis B: Environmental

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“…rather than a CSTR model. [16] We conclude that the kinetic parameters for the elementary reactions in CO TPD can be successfully estimated from the model presented here. We are presently running CO TPD experiments at various initial CO coverages to see if we will observe a trend that can be used to relate CO heat of adsorption with coverage.…”

Section: ( ) ( )mentioning

confidence: 53%

Atomic-Scale Design of Iron Fischer-Tropsch Catalysts; A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

Mavrikakis¹,

Dumesic²,

Nabar³

et al. 2008

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This work focuses on (1) searching/summarizing published Fischer-Tropsch synthesis (FTS) mechanistic and kinetic studies of FTS reactions on iron catalysts; (2) preparation and characterization of unsupported iron catalysts with/without potassium/platinum promoters; (3) measurement of H 2 and CO adsorption/dissociation kinetics on iron catalysts using transient methods; (3) analysis of the transient rate data to calculate kinetic parameters of early elementary steps in FTS; (4) construction of a microkinetic model of FTS on iron, and (5) validation of the model from collection of steady-state rate data for FTS on iron catalysts.Three unsupported iron catalysts and three alumina-supported iron catalysts were prepared by non-aqueous-evaporative deposition (NED) or aqueous impregnation (AI) and characterized by chemisorption, BET, temperature-programmed reduction (TPR), extent-of-reduction, XRD, and TEM methods. These catalysts, covering a wide range of dispersions and metal loadings, are well-reduced and relatively thermally stable up to 500-600°C in H 2 and thus ideal for kinetic and mechanistic studies. Kinetic parameters for CO adsorption, CO dissociation, and surface carbon hydrogenation on these catalysts were determined from temperature-programmed desorption (TPD) of CO and temperature programmed surface hydrogenation (TPSR), temperatureprogrammed hydrogenation (TPH), and isothermal, transient hydrogenation (ITH). A microkinetic model was constructed for the early steps in FTS on polycrystalline iron from the kinetic parameters of elementary steps determined experimentally in this work and from literature values. Steady-state rate data were collected in a Berty reactor and used for validation of the microkinetic model. These rate data were fitted to "smart" Langmuir-Hinshelwood rate expressions derived from a sequence of elementary steps and using a combination of fitted steady-state parameters and parameters specified from the transient measurements. The results provide a platform for further development of microkinetic models of FTS on Fe and a basis for more precise modeling of FTS activity of Fe catalysts.Calculations using periodic, self-consistent Density Functional Theory (DFT) methods were performed on various realistic models of industrial, Fe-based FTS catalysts. Close-packed, most stable Fe(110) facet was analyzed and subsequently carbide formation was found to be facile leading to the choice of the Fe C (110) model representing a Fe facet with a sub-surface C atom. The Pt adatom (Fe Pt (110)) was found to be the most stable model for our studies into Pt promotion and finally the role of steps was elucidated by recourse to the defected Fe(211) facet. Binding Energies(BEs), preferred adsorption sites and geometries for all FTS relevant stable species and intermediates were evaluated on each model catalyst facet. A mechanistic model (comprising of 32 elementary steps involving 19 species) was constructed and each elementary step therein was fully characterized with respect to its thermochemi...

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Temperature-programmed desorption as a tool to extract quantitative kinetic or energetic information for porous catalysts

Cited by 50 publications

References 21 publications

Non-Calorimetric Determination of the Adsorption Heat of Volatile Organic Compounds under Dynamic Conditions

Non-Calorimetric Determination of the Adsorption Heat of Volatile Organic Compounds under Dynamic Conditions

Toluene oxidation over ZrO2-based gasification gas clean-up catalysts: Part B. Kinetic modeling

Atomic-Scale Design of Iron Fischer-Tropsch Catalysts; A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

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