Intrinsic kinetic model for oxidative dehydrogenation of ethane over MoVTeNb mixed metal oxides: A mechanistic approach

Oxidative dehydrogenation of ethane over mixed metal oxide catalysts: Autothermal or cooled tubular reactor design?

“…Several sets of sequences of elementary steps have been proposed in the literature for ODHE over supported vanadia, 5,7‐11,50 MoVNb, 51,52 and MoVTeNbO catalysts 21,31‐34,53,54 . We propose herein a sequence of elementary steps (Table 1) that under certain conditions reduces to an expression that is first order in ethane and zero order in oxygen and water, consistent with reaction orders measured experimentally.…”

“…[17][18][19] More recently, mixed metal oxides comprised of Mo, V, Te, and Nb have received attention as ODHE catalysts owing to their high ethylene selectivity. [20][21][22][23][24][25][26][27][28][29] For example, Nieto et al 30 reported ethylene selectivities greater than 90% for ethane conversions up to 80% between 613 and 673 K. We note that despite the existence of a significant body of work focusing on synthesizing and evaluating improved catalysts, 21,[31][32][33][34] industrially feasible reactor designs that circumvent the need for catalyst dilution have not been presented thus far in the open literature.…”

Phase-pure M1 MoVNbTeOx/TiO2nanocomposite catalysts: high catalytic performance for oxidative dehydrogenation of ethane

“…Though the MvK mechanism features a 0-order dependence with respect to oxygen, 57 it does not mean that the re-oxidation of catalysts is not important in the ODHE process. In a mechanistic hypothesis of the ODHE reaction for M1 catalysts, based on the MvK mechanism, a migration process of surface oxygen (O*) to lattice oxygen (M OX ) was proposed by Donaubauer et al 35 They suggested that the re-oxidation of lattice oxygen will be the rate-controlling step under low oxygen partial pressure. From the fitting results, the difference of k 1 between M1/40TiO 2 (3.16 × 10 −6 Pa s −1 ) and M1 (5.08 × 10 −6 Pa s −1 ) is almost consistent with the total V 5+ content.…”

“…18 Recently, Ganjkhanlou et al 34 found that the interaction with anatase phase TiO 2 may lead to a modification of the redox properties of the VO x species. Donaubauer et al 35 proposed the transition from surface oxygen (O*) to lattice oxygen (M OX ) in their hypothesis for the ODHE process mechanism of MoVNbTeO x catalysts. In light of these, we select TiO 2 as a potential promoter in this work due to its redox properties (Ti 3+ /Ti 4+ ) and high surface area, 36 which may have a synergy with the M1 phase during ODHE.…”

Unravelling the redox mechanism and kinetics of a highly active and selective Ni-based material for the oxidative dehydrogenation of ethane

“…Catalytic ODH-C 2 kinetics has essentially been investigated over vanadium-based materials. 8,10,51–64 They have, in general, followed the power-law (PL) approach, 8,65 the Langmuir–Hinshelwood–Hougen–Watson (LHHW) formalism, 52,56,58,59 the Mars and van Krevelen (MvK) formalism, 52,55 the Eley–Rideal (ER) formalism, 10,59 or a combination of them. 52 To the best of our knowledge, only three publications reported on modelling ODH-C 2 on Ni-based materials.…”