Porous chitosan-MnO2 nanohybrid: a green and biodegradable heterogeneous catalyst for aerobic oxidation of alkylarenes and alcohols

A porous chitosan-manganese dioxide (PC-MnO2) nanohybrid was synthesized using an in situ reduction method, in which potassium permanganate solution and nanoporous chitosan acted as precursor and reducing agent. The chemical and structural properties of PC-MnO2 were characterized using scanning and transmission electron microscopies, X-ray diffraction, thermogravimetric analysis and Fourier transform infrared spectroscopy. Highly dispersed MnO2 nanoparticles in a matrix of porous chitosan showed high catalytic activity for selective aerobic oxidation of alkylarenes and alcohols without using any bases or expensive oxidants. Short reaction time, ease of product separation by filtration and recyclability of the catalyst make it environmentally and economically favoured for the synthesis of versatile aldehydes and ketones. Copyright (c) 2015 John Wiley & Sons, Ltd.