The atomic origin of high catalytic activity of ZnO nanotetrapods for decomposition of ammonium perchlorate

• Published in: CrystEngComm 2014-01, Vol.16 (4), p.570-574
• Main Authors: Tang, Gen, Wen, Yanwei, Pang, Aiming, Zeng, Dawen, Zhang, Yungang, Tian, Shouqin, Shan, Bin, Xie, Changsheng
• Format: Article
• Language: English
• Subjects: Catalysts
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/C3CE41435C

Distinct from the common well faceted ZnO nanorods (R-ZnO), ZnO nanotetrapods (T-ZnO) exhibited a remarkable catalytic activity for the thermal decomposition of ammonium perchlorate (AP): the activation energy at high temperature decomposition (HTD) was significantly decreased to 111.9 kJ mol super(-1), much lower than 162.5 kJ mol super(-1) for pure AP and 156.9 kJ mol super(-1) for AP with R-ZnO. This was attributed to more abundant atomic steps on the surface of T-ZnO than that of R-ZnO, as evidenced by HRTEM and density function theory (DFT) calculations. It was shown that the initiation step of perchloric acid (PA) decomposition happened much faster on stepped T-ZnO edges, resulting in the formation of active oxygen atoms from HClO sub(4). The formed oxygen atoms would subsequently react with NH sub(3) to produce HNO, N sub(2)O and NO species, thus leading to an obvious decrease in the activation energy of AP decomposition. The proposed catalytic mechanism was further corroborated by the TG-IR spectroscopy results. Our work can provide atomic insights into the catalytic decomposition of AP on ZnO nanostructures.