Synthesis of ultra-thin 2D MnO2 nanosheets rich in oxygen vacancy defects and the catalytic oxidation of n-heptane

Abstract

N-heptane (C7H16) is a kind of VOCs from a wide range of sources, which harm to the atmosphere and human health. So far, most of the researches on C7H16 have focused on catalytic cracking rather than its low temperature degradation. As a kind of long straight carbon chain alkanes, the study of catalytic oxidation of C7H16 has a certain guiding value for the degradation and mechanism analysis of complex organic compounds. In our study, 2D birnessite-MnO2 nanosheet with the thickness of 1.7–2.5 nm was successfully prepared and it can achieve complete conversion of C7H16 at 252.31 °C, which is better than the bulk catalyst. The characterization (such as TEM, XRD, etc.) and kinetic experiments results showed that it has good catalytic oxidation performance due to its ultra-thin, large specific surface, abundant oxygen vacancies and excellent electron transfer efficiency, which not only exposes more surface atoms, but also absorbs more gaseous O2 and rapidly transforms into reactive oxygen species (ROS) that can participate in catalytic oxidation. Surface reactive oxygen species play an important role in catalytic oxidation due to the formation of surface oxygen vacancies.