Modulating Lattice Oxygen in Dual-Functional Mo-V-O Mixed Oxides for Chemical Looping Oxidative Dehydrogenation

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Oxygen chemistry is crucial for selective C-H bond cleavage in alkane dehydrogenation.
• Conventional oxidative dehydrogenation (ODH) often suffers from low alkene selectivity due to over-oxidation.
• Developing efficient catalysts for selective alkane functionalization remains a significant challenge.

Purpose of the Study:

• To develop a novel catalytic system for selective propane to propylene conversion.
• To investigate an alternative chemical looping oxidative dehydrogenation (CL-ODH) approach.
• To understand the role of metal-oxygen interactions in enhancing selectivity.

Main Methods:

• Synthesis and characterization of dual-functional Mo-V-O mixed oxides.
• Evaluation of catalytic performance in propane dehydrogenation at 500 °C.
• Investigation of reaction mechanisms involving lattice oxygen and atomic-scale doping.
• Analysis of catalyst stability over 100 dehydrogenation-regeneration cycles.

Main Results:

• Achieved 89% propylene selectivity at 36% propane conversion using Mo-V-O catalysts.
• Demonstrated high catalyst stability over 100 cycles.
• Identified precise modulation of bulk lattice oxygen via Mo doping as key to selectivity.
• Showed that increasing V-O bond binding energy is critical for propylene selectivity.

Conclusions:

• The CL-ODH approach with Mo-V-O catalysts offers a promising strategy for selective alkane dehydrogenation.
• Atomic-scale doping and modulation of metal-oxygen bonds are critical for catalyst performance.
• This study provides fundamental insights into metal-oxygen chemistry for selective oxidation reactions.