Unveiling the contribution of Mo, V and W oxides to coking in catalytic glycerol oxidehydration.

• The contribution of Mo, V and W oxides supported on Mt to coking was unveiled. • Quantitative analyses revealed that coke was predominantly formed in Mo-Mt and W-Mt catalysts. • Composition of Mo5+ and Mo6+ prior to the reaction hindered full oxidation to Mo6+. • Incorporation of V oxide in mixed Mo-V-Mt and W-V-Mt helped reduce coke. Mo, V and W oxides supported on montmorillonite (Mt) have shown good activity in catalytic glycerol oxidehydration. However, these catalysts deactivate rapidly due to coking. Understanding the role of Mo, V and W oxides in coke formation is essential to overcome the coking problem. Herein, individual and combination of Mo, V and W oxides supported on Mt were investigated to reveal the contribution of Mo, V and W oxides to coke formation. Among single metal oxide catalysts, Mo-Mt and W-Mt suffered more from coke formation than V-Mt. A mixture of Mo5+ and Mo6+ in the Mo-Mt catalyst hindered full oxidation during the oxidehydration, thus promoting coking. The oxidation of V4+ to V5+ helped diminish coke in mixed Mo-V-Mt and W-V-Mt. This work is expected to provide new information for designing high-performance Mo, V and W oxide catalysts with superior coke resistance. [Display omitted] [ABSTRACT FROM AUTHOR]