Characterization of MoVTeNbOx Catalysts during Oxidation Reactions Using In Situ/Operando Techniques: A Review

Abstract

Light alkanes are abundant in shale gas resources. The bulk mixed metal oxide MoVTe(Sb)NbO x catalysts play a very important role in dehydrogenation and selective oxidation reactions of these short hydrocarbons to produce high-value chemicals. This catalyst system mainly consists of M1 and less-active M2 crystalline phases. Due to their ability to directly monitor the catalysts under the relevant industrial conditions, in situ/operando techniques can provide information about the nature of active sites, surface intermediates, and kinetics/mechanisms, and may help with the synthesis of new and better catalysts. Sophisticated catalyst design and understanding is necessary to achieve the desired performance (activity, selectivity, lifetime, etc.) at reasonable reaction conditions (temperature, pressure, etc.). This article critically reviews the progress made in research of these MoVTe(Sb)NbO x catalysts in oxidation reactions mainly through in situ/operando techniques and suggests the future direction needed to realize the industrialization of these catalysts.

Probing the Positions of TeO Moieties in the Channels of the MoVNbTeO M1 Catalyst: A Density Functional Theory Model Study

“…Since the discovery of the MoVNbTeO mixed-metal oxide catalyst [3], significant effort was devoted in understanding this catalyst. Studies in this field range from synthesizing MoVNbTeO and its variants [9][10][11], characterizing the structure of these materials [12][13][14][15][16][17][18][19][20], elaborating the catalytic mechanism [21][22][23], to elucidating how the metal centers and V 5+ /V 4+ pairs are distributed in the material [24][25][26][27][28]. It is well accepted that the V 5+ species are responsible for activating the alkanes over this catalyst [21,27,29,30], yet clarifying their location remains as one of the challenges.…”

Site specific and localized structural displacements in open structured multimetallic oxides

“…17,18 They have been the subject of numerous studies that focused on the understanding of their catalytic and structural properties also including operando/ in situ investigations. 7,[9][10][11][12][13]16,[19][20][21][22][23][24][25][26][27][28][29] A crystallographic model is shown in Fig. 1A.…”

Influence of Tight Confinement on Selective Oxidative Dehydrogenation of Ethane on MoVTeNb Mixed Oxides

“…Oxidative dehydrogenation (ODH) of small alkanes provides an important energy-efficient route to the production of alkenes that constitute essential building blocks of the chemical industry. , Mixed bulk oxides of Mo, V, Nb, Te, and other elements (Sb, Ta, and W), arranged in an orthorhombic crystalline form, known as the M1 phase, catalyze ethane ODH with exceptionally high selectivity to ethylene at moderate reaction temperatures. − These oxides also play an important role in selective formation of acrolein, acrylic acid, or acrylonitrile directly from a propane feed, instead of the more conventional propene-based processes. − Relations among synthesis methods, structures, and catalytic functions of these solids are being probed extensively. − …”