Surface active sites for dehydrogenation reaction of isopropanol on manganese dioxide

The existence of O2− or HOO− has been observed by epr at g = 2.008 and 2.03 on samples of manganese dioxide pretreated between 100 and 400 °C. The relative value of the epr absorption decreased with an increase in the pretreatment temperature. The concentration of surface traps determined by the DPPH method was nearly proportional to the relative value of the epr absorption on manganese dioxide. Furthermore, O2− or HOO− on the surface of manganese dioxide acts as an active site during the dehydrogenation reaction of isopropanol.