From a Novel Energetic Coordination Polymer Precursor to Diverse Mn₂O₃ Nanostructures: Control of Pyrolysis Products Morphology Achieved by Changing the Calcination Atmosphere

A novel strategy to fabricate diverse α-Mn₂O₃ nanostructures from the nitrogen-rich energetic coordination polymer (ECP) [Mn­(BTO)­(H₂O)₂]_n (BTO = 1H,1′H-[5,5′-bitetrazole]-1,1′-bis­(olate)) has been developed by changing the pyrolysis atmosphere. The results show that the energetic constituent and calcination environment are vital factors to get quite different morphologies of pyrolysis products. When the calcination reaction occurs under N₂ or O₂, rod-shaped mesoporous α-Mn₂O₃ with a large specific surface of 50.2 m²·g^–1 and monodispersed α-Mn₂O₃ with a size of 10–20 nm can be obtained, respectively, which provides a new platform to prepare specific shapes and sizes of manganese oxides. Inspired by the transformation of 1 under O₂ atmosphere, we applied an in situ generated ultrafine α-Mn₂O₃ catalyst in the decomposition of ammonium perchlorate (AP) using ECP 1 as a precursor. The catalytic process of AP shows a remarkable decreased decomposition temperature (271 °C) and a narrower decomposition interval (from 253 to 275 °C). To our best knowledge, with such a low metal loading (0.65 wt %), the catalytic performance of in situ generated monodispersed ultrafine α-Mn₂O₃ is by far the best, which suggests that this ultraefficient catalyst has great potential in AP-based propellants.