Chemical Engineering Journal, Vol.296, 217-224, 2016
Kinetics study for the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate over MoVNbOx based catalysts
Mo0.61V0.31Nb0.08Ox and Mo0.61V0.31Nb0.08Ox/TiO2 catalysts were prepared for the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate in a continuous fixed -bed reactor under atmospheric pressure. The transport effects and catalytic stability over Mo0.61V0.31Nb0.08Ox/TiO2 catalyst were investigated to ensure that the experimental results were not significantly influenced by interphase transportation and catalytic deactivation. Mo0.61V0.31Nb0.08Ox/TiO2 catalyst exhibited extremely higher conversion rate of ethyl lactate but relatively lower apparent activation energy in comparison with Mo0.61V0.31Nb0.08Ox indicating its superior catalytic activity beneficial from the good dispersion of active Mo0.61V0.31Nb0.08Ox component on TiO2 support. It was experimentally verified that the conversion rate of ethyl lactate was simply first-order dependence on the partial pressure of O-2 over Mo0.61V0.31Nb0.08Ox/TiO2. The analysis of elementary reaction steps and the derivation of reaction rate equation were performed based on typical Mars-van Krevelen (MvK) redox mechanism under the assumption that surface oxygen vacancies were the most abundant species. The obtained reaction rate equation was a first -order function towards O-2 partial pressure, which was good consistent with the experimental kinetics results. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Oxidative dehydrogenation;Ethyl lactate;Ethyl pyruvate;MoVNbOx;Kinetics;Elementary reaction step