Ozonolysis with MnO2: A Safe and Cost-Efficient Way for Producing Aldehydes and Ketones

Ozonolysis is a highly promising reaction for biomass valorization due to high efficiency, value-added carbonyl products, cheap oxidant, and mild conditions. However, the generation and accumulation of explosive peroxides during ozonolysis can be a risk and obstacle for large application. Herein, we propose a simple method that treats ozonolysis products with MnO2 to decompose and reduce the complex peroxides. Here, 60–90% peroxides can be removed within minutes at ambient conditions. Solvent and substrate structures influence MnO2 activity. We further propose a novel in situ MnO2-assisted ozonolysis, which restrains formation of peroxides while promotes aldehydes formation. Kinetic investigations indicated that H2O2 decomposition at low concentration is a first-order reaction, while it accelerated at high concentration due to an involvement of second-order decomposition of an organic peroxide generated in a rapid equilibrium with H2O2 and aldehyde. This work suggests that ozonolysis enables greener biomass valorization with more sustainable carbonyl products.