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Formic Acid Decomposition over V-Ti Oxide Catalyst: Mechanism and Kinetics Full article

Journal Molecular Catalysis
ISSN: 2468-8231
Output data Year: 2017, Volume: 430, Pages: 54-62 Pages count : 9 DOI: 10.1016/j.molcata.2016.12.010
Tags Formic acid decomposition, IR spectroscopy, Transient kinetic, V-Ti oxide catalyst
Authors Sadovskaya E.M. 1,2 , Chesalov Yu.A. 1,2 , Goncharov V.B. 1 , Sobolev V.I. 1 , Andrushkevich T.V. 1
Affiliations
1 Boreskov Insitute of Catalysis SB RAS, Pr. Lavrientieva 5, Novosibirsk, 630090, Russia
2 Novosibirsk State University, Pirogova Str. 2, Novosibirsk, 630090, Russia

Funding (1)

1 Federal Agency for Scientific Organizations V.44.2.7.

Abstract: A detailed kinetic model for formic acid (HCOOH) decomposition on oxide vanadium-titanium (7.3%V2O5/92.7%TiO2) catalyst has been developed based on transient kinetic studies and IR spectroscopy in situ. Formic acid decomposition to CO2 (dehydrogenation) and to CO (dehydration) proceeds via different mechanistic routes. Dehydrogenation proceeds via the conventional “formate” mechanism and include reversible dissociative adsorption of formic acid on vanadyl group V = O. The oxygen of the group acts as a proton acceptor whereas a vanadium cation is a formate anion stabilizer. Formate complexes can recombinate with protons and desorb in the form of formic acid or decompose to CO2. Dehydration reaction follows a different mechanism. An interaction of the coordination unsaturated sites V+-O− with HCOOH leads to the synchronous cleavage of the Csingle bondOH and Csingle bondH bonds. Meanwhile the two OH hydroxyl groups are formed and CO molecule is evolved into gas phase. The path is completed by water desorption. The rate constants and activation energies of elementary steps are calculated for a dehydrogenation and dehydration reactions. The rate-limited steps of the reaction are formate decomposition stage for dehydrogenation path (Ea = 60 kJ/mol) and water desorption stage for dehydration rout (Ea = 100 kJ/mol). The difference in the values of activation energies results in an increase of selectivity towards CO with reaction temperature elevation. Water inhibits formic acid decomposition. In the case the dehydrogenation, it connected with adsorption displacement of formates with water, whereas, in the case of dehydration, it is associated with an active centers blocking by adsorbed water. The developed kinetic model takes into account the water effect of both routs and satisfactorily describes the steady state reaction behavior.
Cite: Sadovskaya E.M. , Chesalov Y.A. , Goncharov V.B. , Sobolev V.I. , Andrushkevich T.V.
Formic Acid Decomposition over V-Ti Oxide Catalyst: Mechanism and Kinetics
Molecular Catalysis. 2017. V.430. P.54-62. DOI: 10.1016/j.molcata.2016.12.010 WOS Scopus РИНЦ AN OpenAlex
Dates:
Submitted: Sep 27, 2016
Accepted: Dec 8, 2016
Published online: Mar 31, 2017
Published print: Apr 1, 2017
Identifiers:
Web of science: WOS:000400549400007
Scopus: 2-s2.0-85029627007
Elibrary: 31059027
Chemical Abstracts: 2016:2146404
OpenAlex: W2560670408
Citing:
DB Citing
Web of science 16
Scopus 18
Elibrary 15
OpenAlex 18
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