Design and synthesis of highly active MoVTeNb-oxides for ethane oxidative dehydrogenation

Abstract

Ethane oxidative dehydrogenation (ODH) is an alternative route for ethene production. Crystalline M1 phase of Mo-V mixed metal oxide is an excellent catalyst for this reaction. Here we show a hydrothermal synthesis method that generates M1 phases with high surface areas starting from poorly soluble metal oxides. Use of organic additives allows control of the concentration of metals in aqueous suspension. Reactions leading to crystalline M1 take place at 190 °C, i.e., approximately 400 °C lower than under current synthesis conditions. The evolution of solvated polyoxometalate ions and crystalline phases in the solid is monitored by spectroscopies. Catalysts prepared by this route show higher ODH activity compared to conventionally prepared catalysts. The higher activity is due not only to the high specific surface area but also to the corrugated lateral termination of the M1 crystals, as seen by atomic resolution electron microscopy, exposing a high concentration of catalytically active sites.

On the Promoting Effects of Te and Nb in the Activity and Selectivity of M1 MoV-Oxides for Ethane Oxidative Dehydrogenation

“…Synthesis of MoV(TeNb)O x materials was performed as described in a prior contribution [21]. In brief, MoO 3 , V 2 O 5 , TeO 2 , Nb 2 O 5 •1.5H 2 O, citric acid (CA), oxalic acid (OA) and mono ethylene glycol (EG) were dispersed in millipore grade H 2 O.…”

“…Here, we study the role of the metal composition of M1 catalysts on the product distribution, activity and selectivity in oxidative dehydrogenation of ethane. Recently, we developed a new synthesis method that enables the preparation of phase pure M1 MoV(Te,Nb)O x with significantly higher surface and intrinsically higher density of active sites [21]. Using this method, we have prepared a series of high surface area M1 materials with identical V content but different Te and Nb concentrations.…”

Defect-rich TiO2 in situ evolved from MXene for efficiently oxidative dehydrogenation of ethane

“…Metal oxide catalysts are widely studied in the ODH of ethane to ethylene as for their adjustable surface properties from metal coordination environment, redox properties, and its acidity or basicity 1,8 . The facile reducible ones such as V-based, Mo-based, Ni-based materials are preferred due to su cient active oxygen species for ethane conversion [9][10][11] .…”

Direct electrochemical synthesis of oxygenates from ethane using phosphate-based electrolysis cells

“…The number of studies on effective ethane utilization has increased steeply in recent years. Most studies have focused on ethylene production, [1][2][3][4][5][6] while few have addressed oxygenate production such as acetaldehyde and ethanol. [7][8][9] These products are difficult to obtain directly from ethane because ethane activation and suppression of over-oxidation of oxygenates are challenging.…”

“…15 C 2 H 5 OH -CH 3 CHO + H 2 (2) Because H 2 O was not introduced in the anode in the ethanol oxidation test, H + production from C 2 H 5 OH is a requisite for anodic current generation. Thus, the reactions shown in eqn (3) and (4) might occur, and as a consequence C 2 H 4 and CH 3 CHO are produced. This indicates that ethanol generated from ethane can be oxidized easily under the anodic polarized conditions.…”