Pt/MnO2 nanosheets: facile synthesis and highly efficient catalyst for ethylene oxidation at low temperature

Transition metal oxides (TMOs) have been playing an indispensible role in the catalysis of redox reactions. In particular, two dimensional TMOs expose their surface/edge sites to a large extent, which brings unique catalytic features such as greatly enhanced catalytic activities. Here a series of MnO2 nanosheets have been facilely synthesized by a simple redox reaction between KMnO4 and 2-(N-morpholino)ethane sulfonic acid (MES) at room temperature. Among the obtained MnO2 samples, MnO2-48 h showed the highest performance in removing C2H4 resulting from its highest concentration of surface active oxygen species. To further improve the oxidation activity of the catalyst, a small amount of Pt nanoparticles (NPs) was subsequently loaded on MnO2 nanosheets (Pt/MnO2) by a colloidal deposition method. The Pt/MnO2 demonstrated enhanced catalytic performance and maintained complete removal of 20 ppm C2H4 at 50 °C for at least 12 h, which can be attributed to the large amount of adsorbed oxygen species and synergetic catalytic effect between Pt and the MnO2 support.