Yang Fan, Pei Jiayun, Zhao Haiyan
Department of Mechanical Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, People's Republic of China.
Langmuir. 2022 Mar 29;38(12):3844-3851. doi: 10.1021/acs.langmuir.2c00027. Epub 2022 Mar 17.
The employment of catalysts is an effective way to improve ammonium perchlorate (AP) decomposition performance during the combustion of composite solid propellants. Understanding the micromechanism of catalysts at the atomic level, which is hard to be observed by experiments, can help attain more excellent decomposition properties of AP. In this study, first-principles simulations based on density functional theory were used to explore the effect of the graphene catalyst and iron oxide (FeO) catalyst on AP decomposition. Considering the transfer of a H atom during AP decomposition, the most stable adsorption sites for aforementioned catalysts were found: the top of the C atom of the graphene surface with the adsorption energy of -0.378 eV and the top of the Fe atom of the FeO surface with the adsorption energy of -1.596 eV. On the basis of adsorption results, our transition state calculations indicate that, in comparison to control groups, graphene and FeO can reduce the activation energy barrier by ∼19 and ∼37%, respectively, to promote AP decomposition with a transfer process of a H atom on the catalyst surface. Our calculations provide a way for explaining the micromechanism of the catalytic activity of graphene and FeO nanocomposites in AP decomposition and guide experimental applications of graphene and FeO for catalytic reactions.
在复合固体推进剂燃烧过程中,使用催化剂是提高高氯酸铵(AP)分解性能的有效方法。在原子水平上理解催化剂的微观机制,这很难通过实验观察到,有助于获得更优异的AP分解性能。在本研究中,基于密度泛函理论的第一性原理模拟被用于探究石墨烯催化剂和氧化铁(FeO)催化剂对AP分解的影响。考虑到AP分解过程中H原子的转移,发现了上述催化剂最稳定的吸附位点:石墨烯表面C原子顶部,吸附能为-0.378 eV;FeO表面Fe原子顶部,吸附能为-1.596 eV。基于吸附结果,我们的过渡态计算表明,与对照组相比,石墨烯和FeO可分别降低活化能垒约19%和37%,以通过催化剂表面H原子的转移过程促进AP分解。我们的计算为解释石墨烯和FeO纳米复合材料在AP分解中的催化活性微观机制提供了一种方法,并指导石墨烯和FeO在催化反应中的实验应用。