“State defining” experiment in chemical kinetics—primary characterization of catalyst activity in a TAP experiment

Shekhtman, Sergiy O.; Yablonsky, Gregory S.; Gleaves, John; Fushimi, Rebecca

doi:10.1016/j.ces.2003.08.005

Cited by 61 publications

(52 citation statements)

References 15 publications

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“…After the initial analysis, these Laplace reactivities can be further interpreted in terms of detailed mechanisms and kinetic models [34]. This approach was a major step in the development of "model-free" characterization of catalysts and has been applied to analyze several reactions of practical value [42,43], but it suffers from two major limitations.…”

Section: Temporal Analysis Of Productsmentioning

confidence: 99%

Rate-Reactivity Model: A New Theoretical Basis for Systematic Kinetic Characterization of Heterogeneous Catalysts

Yablonsky

Redekop

Constales

et al. 2016

Int. J. Chem. Kinet.

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Non-steady-state kinetic measurements contain a wealth of information about catalytic reactions and other gas-solid chemical interactions, which is extracted from experimental data via kinetic models. The standard mathematical framework of microkinetic models, which are typically used in computational catalysis and for advanced modeling of steady-state data, encounters multiple challenges when applied to non-steady-state data. Robust phenomenological models, such as the steady-state Langmuir-Hinshelwood-Hougen-Watson equations, are presently unavailable for non-steady-state data. Herein, a novel modeling framework is proposed to fulfill this need. The rate-reactivity model (RRM) is formulated in terms of experimentally observable quantities including the gaseous transformation rates, concentrations, and surface uptakes. The model is linear with respect to these quantities and their pairwise products, and it is also linear in terms of its parameters (reactivities). The RRM parameters have a clear physicochemical meaning and fully characterize the kinetic behavior of a specific RATE-REACTIVITY MODEL FOR KINETIC CHARACTERIZATION OF HETEROGENEOUS CATALYSTS 305catalyst state, but unlike microkinetic models that rely on hypothetical surface intermediates and specific reaction networks, the RRM does not require any assumptions regarding the underlying mechanism. The systematic RRM-based procedure outlined in this paper enables an effective comparison of various catalysts and the construction of more detailed microkinetic models in a rational manner. The model was applied to temporal analysis of products pulseresponse data as an example, but it is more generally applicable to other non-steady-state techniques that provide time-resolved rates and concentrations. Several numerical examples are given to illustrate the application of the model to simple model reactions. C 2016 Wiley Periodicals, Inc. Int J Chem Kinet 48: [304][305][306][307][308][309][310][311][312][313][314][315][316][317] 2016

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Section: Temporal Analysis Of Productsmentioning

confidence: 99%

Rate-Reactivity Model: A New Theoretical Basis for Systematic Kinetic Characterization of Heterogeneous Catalysts

Yablonsky

Redekop

Constales

et al. 2016

Int. J. Chem. Kinet.

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“…The vacuum chamber is specially designed to give a very high pumping speed so that responses measured at the mass spectrometer accurately reflect gas interactions in the microreactor. A detailed description of the TAP-2 apparatus and experimental methodology can be found in the literature [25][26][27][28][29][30].…”

Section: Kinetic Characterizationmentioning

confidence: 99%

“…The TAP-2 system has the ability to perform vacuum pulse response experiments and atmospheric pressure experiments, including steady-state, steptransient, and temperature programmed experiments [25][26][27][28][29]. A TAP-2 system consists of three main parts: a pulse valve/manifold assembly, a microreactor, and vacuum chamber with a mass spectrometer (Fig.…”

Section: Kinetic Characterizationmentioning

confidence: 99%

Techniques for Fabricating Nanoscale Catalytic Circuits

et al. 2008

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This paper describes the development of a new technique, atomic beam deposition (ABD), for the fabrication of catalysts with different active sites capable of catalyzing different chemical reactions. Using ABD, submonolayer amounts of Te and Cu atoms were deposited on vanadyl pyrophosphate (VPO) catalyst particles, and precise non-steady-state kinetic characterization was performed using the temporal analysis of products (TAP) reactor immediately following deposition. Results from TAP Knudsen pulse response experiments determine if small changes in the metal surface composition would produce detectable changes in catalytic properties. Partial oxidation of 1-butene to furan was used as the test reaction. Furthermore, this paper also demonstrates the sensitivity of the TAP reactor by measuring oxygen uptake on a single 350 lm diameter polycrystalline Pt particle packed in a bed with 100,000 inert quartz particles of similar dimensions. The Pt experiments demonstrate the precise manipulation of surface oxygen content.

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“…Unsteady kinetic characterization of catalytic devices is often made through pulse-response methods such as Temporal Analysis of Products (TAP) methods [49][50][51][52] and Unsteady-State Processes in Catalysis (USPC) [53]. These techniques typically apply to high-vacuum conditions, where the molecular mean free path is significant compared to the characteristic size of the device.…”

Section: Heterogeneous Catalysis In Pulsed-flow Reactorsmentioning

confidence: 99%

Simulating Engineering Flows through Complex Porous Media via the Lattice Boltzmann Method

Krastev

Falcucci

2018

Energies

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Abstract:In this paper, recent achievements in the application of the lattice Boltzmann method (LBM) to complex fluid flows are reported. More specifically, we focus on flows through reactive porous media, such as the flow through the substrate of a selective catalytic reactor (SCR) for the reduction of gaseous pollutants in the automotive field; pulsed-flow analysis through heterogeneous catalyst architectures; and transport and electro-chemical phenomena in microbial fuel cells (MFC) for novel waste-to-energy applications. To the authors' knowledge, this is the first known application of LBM modeling to the study of MFCs, which represents by itself a highly innovative and challenging research area. The results discussed here essentially confirm the capabilities of the LBM approach as a flexible and accurate computational tool for the simulation of complex multi-physics phenomena of scientific and technological interest, across physical scales.

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“State defining” experiment in chemical kinetics—primary characterization of catalyst activity in a TAP experiment

Cited by 61 publications

References 15 publications

Rate-Reactivity Model: A New Theoretical Basis for Systematic Kinetic Characterization of Heterogeneous Catalysts

Rate-Reactivity Model: A New Theoretical Basis for Systematic Kinetic Characterization of Heterogeneous Catalysts

Techniques for Fabricating Nanoscale Catalytic Circuits

Simulating Engineering Flows through Complex Porous Media via the Lattice Boltzmann Method

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