Shen Chen, Yan Shi, Yao Jie, Ren Hui, Guo Xueyong, Nie Jianxin, Ou Yapeng, Jiao Qingjie, Luo Yunjun
State Key Laboratory of Explosion of Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.
Phys Chem Chem Phys. 2024 May 29;26(21):15393-15404. doi: 10.1039/d3cp06133g.
The combustion agglomeration of nano-aluminum (nAl) powder leads to incomplete combustion, which seriously hinders its application as metal fuel. In this work, nAl@AlF composites were produced by coating nAl with AlF a facile chemical deposition method. TEM and SEM analyses indicated that the AlF layer was evenly coated on the surface of nAl with a thickness of 4.6-9.1 nm, thereby varying the quantity of AlF applied. Experimental results from combustion indicated that the prepared nAl@AlF composites exhibit superior combustion efficiency, a higher combustion rate, and reduced combustion agglomeration as compared to raw nAl. Contrary to the widely accepted explanation that volatilization of AlF hinders Al combustion agglomeration, we proved that the gas-solid reaction between nAl and AlF plays an important role in inhibiting the sintering of nAl particles produced. The gaseous intermediate (, AlOF and HF) released from the hydrolysis of AlF could reduce the diffusion barrier of AlO to facilitate the reaction of Al core, which enhances the combustion reaction kinetics. More importantly, these gaseous products actively participate in the reaction cycle to continuously exert their catalytic effects.
纳米铝（nAl）粉的燃烧团聚导致燃烧不完全，这严重阻碍了其作为金属燃料的应用。在这项工作中，通过一种简便的化学沉积方法用AlF包覆nAl制备了nAl@AlF复合材料。透射电子显微镜（TEM）和扫描电子显微镜（SEM）分析表明，AlF层均匀地包覆在nAl表面，厚度为4.6 - 9.1纳米，从而改变了AlF的用量。燃烧实验结果表明，与原始nAl相比，制备的nAl@AlF复合材料表现出更高的燃烧效率、更高的燃烧速率和减少的燃烧团聚。与普遍接受的AlF挥发阻碍Al燃烧团聚的解释相反，我们证明了nAl与AlF之间的气固反应在抑制所产生的nAl颗粒烧结方面起着重要作用。AlF水解释放出的气态中间体（ 、AlOF和HF）可以降低AlO的扩散势垒，促进Al核的反应，从而增强燃烧反应动力学。更重要的是，这些气态产物积极参与反应循环以持续发挥其催化作用。
