Zhou Linyu, Cao Shaobo, Zhang Liangliang, Xiang Guolei, Wang Jiexin, Zeng Xiaofei, Chen Jianfeng
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, PR China; Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing, 100029, PR China.
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, PR China; Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, Beijing, 100029, PR China.
J Hazard Mater. 2020 Jun 15;392:122358. doi: 10.1016/j.jhazmat.2020.122358. Epub 2020 Feb 19.
Crystal facets can affect the catalytic decomposition of ammonium perchlorate, but the underlying mechanisms have long remained unclear. Here, we use the nanorods, nanosheets and nanocubes of CoO catalysts exposing {110}, {111} and {100} facets as model systems to investigate facet effects on catalytic AP decomposition. The peak temperature of high temperature decomposition (HTD) process (T) of AP by nanorods, nanosheets and nanocubes CoO decrease from 437.0 °C to 289.4 °C, 299.9 °C and 326.3 °C, respectively, showing obvious facet effects. We design experiments about AP decomposition under different atmospheres to investigate its mechanism and verify that the accumulation of ammonia (NH) on AP surface can inhibit its decomposition and that the facet effects are related to the adsorption and oxidation of NH. The binding energies of NH on the {110}, {111} and {100} planes calculated via density functional theory (DFT) are -1.774 eV, -1.638 eV, and -1.354 eV, respectively, indicating that the {110} planes are more favorable for the adsorption of NH. Moreover, the {110} planes are readily to form CoNO structure, which benefits the further oxidation of the NH.
晶面会影响高氯酸铵的催化分解，但潜在机制长期以来一直不清楚。在此，我们使用暴露{110}、{111}和{100}晶面的CoO催化剂纳米棒、纳米片和纳米立方体作为模型体系，来研究晶面对高氯酸铵催化分解的影响。纳米棒、纳米片和纳米立方体CoO催化高氯酸铵高温分解（HTD）过程的峰值温度（T）分别从437.0℃降至289.4℃、299.9℃和326.3℃，显示出明显的晶面效应。我们设计了不同气氛下高氯酸铵分解的实验来研究其机制，并证实高氯酸铵表面氨（NH）的积累会抑制其分解，且晶面效应与NH的吸附和氧化有关。通过密度泛函理论（DFT）计算得到NH在{110}、{111}和{100}平面上的结合能分别为-1.774 eV、-1.638 eV和-1.354 eV，表明{110}平面更有利于NH的吸附。此外，{110}平面易于形成CoNO结构，这有利于NH的进一步氧化。
