Methanol oxidation using ozone on titania-supported vanadia catalyst

Area of Science:

• Catalysis
• Chemical Engineering
• Environmental Science

Background:

• Methanol oxidation is crucial for industrial processes and pollution control.
• Conventional oxidation methods often require high temperatures and catalysts.
• Ozone's potential as an oxidant in catalytic processes is an area of active research.

Purpose of the Study:

• To investigate ozone-enhanced catalytic oxidation of methanol using a V2O5/TiO2 catalyst.
• To determine optimal reaction conditions for complete methanol oxidation.
• To elucidate the reaction mechanism and kinetics.

Main Methods:

• Preparation of V2O5/TiO2 catalyst via sol-gel method.
• Characterization using XRD, surface area analysis, and temperature-programmed desorption.
• Methanol oxidation experiments under varying temperatures, ozone-to-methanol ratios, and gas hourly space velocity (GHSV).
• Kinetic modeling using Langmuir-Hinshelwood approach.

Main Results:

• Ozone significantly boosted methanol conversion compared to oxygen, reaching 80% at 100°C over the catalyst.
• Complete oxidation to CO(x) was achieved at 150°C with an ozone-to-methanol ratio of 1.2 and GHSV of 60,000 h⁻¹.
• Lower apparent activation energy (40 kJ/mol) was observed with ozone compared to oxygen (60 kJ/mol).
• Product selectivity shifted from methyl formate to CO(x) with increasing conversion.

Conclusions:

• Ozone-enhanced V2O5/TiO2 catalysis is highly effective for methanol oxidation at mild temperatures.
• The reaction proceeds via a consecutive mechanism, with selectivity dependent on temperature and oxidant ratio.
• Langmuir-Hinshelwood kinetics successfully models the observed reaction behavior.