The catalytic performances of α-MnO2 and δ-MnO2 catalysts synthesized from KMnO4 and ethanol for total oxidation of isopropanol

Abstract

In this study, the catalytic activities of total oxidation of isopropanol (IPA) over MnO2-based catalysts (α-MnO2 and δ-MnO2) were studied and compared. These catalysts were synthesized by an oxidation/reduction route between ethanol and KMnO4 by using dropwise method. Their morphological, structural properties, specific surface area, pore distribution and reducibility were characterized by SEM, XRD, FTIR, N2 isothermal adsorption-desorption, and hydrogen temperature-programmed reduction (H2-TPR). As a result, IPA was significantly oxidized to acetone at low temperature (130 °C) and subsequently to CO2 at higher temperature. α-MnO2 was demonstrated as a better catalyst for total oxidation of IPA compared with δ-MnO2. Over 205 °C, IPA was completely oxidized to CO2. Additionally, the high reducibility of δ-MnO2 was found to be correlated with higher activity of IPA toward acetone at low temperature.