Role of MnO x in Modulating the Reactivity and Sensor Behavior of SnO2/MnO x Nanocomposites in Benzene Detection
Rodion S. Eshmakov, Andrey V. Sherstobitov, Vadim B. Platonov, Andrey V. Smirnov, Andrei A. Eliseev, Marina N. RumyantsevaAbstract
The relationship between the catalytic activity and sensing properties of SnO2/MnOx nanocomposites toward benzene was investigated as a function of the manganese content. The oxidative properties of the nanocomposites were characterized by using the data set from temperature-programmed reduction with hydrogen (TPR-H2) and catalytic benzene conversion. The interaction of the nanocomposites with benzene vapor in dry air was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to elucidate the role of manganese oxides in benzene oxidation. It was found that the oxidative adsorption of benzene, forming surface phenolate species mediated by active Mn(III)/Mn(IV) centers, is crucial for enhancing the sensor response to C6H6. However, excessive MnOx content promotes deep catalytic oxidation of benzene, which ultimately lowers the sensor response of the SnO2/MnOx nanocomposites.