Mn2O3掺杂对MnO催化氧还原性能的提高

The doping of Mn2O3 induced improvement of catalytic performance for oxygen reduction of MnO

摘要:

本文主要研究了纯相MnO以及Mn₂O₃掺杂MnO氧还原催化剂的结构和性能,XRD、SEM、HRTEM等测试表明,氢气还原条件下可以得到Mn₂O₃掺杂的MnO,氨气还原得到纯相MnO。循环伏安(CV)法、Tafal曲线法、时间电流曲线和线性扫描伏安等方法对其催化氧还原性能的研究表明：MnO催化氧还原的峰值电压在-0.1 V到-0.5 V之间,Mn₂O₃的掺杂提高了氧还原峰值电流强度和电压；RDE与RRDE测试表明：Mn₂O₃掺杂MnO的催化氧还原反应主要是4电子反应,而纯相MnO催化氧还原主要是2电子反应。通过本研究表明：Mn₂O₃掺杂提高了MnO的催化氧还原性能,元素不同价态离子的共存提高了催化氧还原反应的活性。

Abstract:

The pure MnO and Mn₂O₃ doped MnO catalysts for oxygen reduction were synthesized by reducing maganese oxide under ammonia and hydrogen atmosphere seperately. X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy tests ascertained the synthesis of the two kinds of catalysts. The cyclic voltammetry, tafel, linear scanning voltammetry and current-time chronoamperometric tests proved that the potential of peak current of oxygen redcution located in the rage of -0.5 to -0.1V. The doping of Mn₂O₃ enhanced the peak potential of oxygen reduction. Both the rotate disc electrode and rotate ring disc electrode tests confirmed that the ORR were major happened through 4-electron reaction style under the catalysis of Mn₂O₃ doped MnO, thus, through 2-electron style onder the catalysis of pure MnO. It is approved that the doping of Mn₂O₃ improved the catalysis of MnO. The coexistence of ions with different valents can promote the promote the catalytic activity.