In Situ X‑ray Diffraction Study of Co–Al Nanocomposites as Catalysts for Ammonia Decomposition
journal contributionposted on 30.07.2015, 00:00 by Ying-Qiu Gu, Xin-Pu Fu, Pei-Pei Du, Dong Gu, Zhao Jin, Yu-Ying Huang, Rui Si, Li-Qiang Zheng, Qi-Sheng Song, Chun-Jiang Jia, Claudia Weidenthaler
Co–Al nanocomposite materials as active and stable catalysts for ammonia decomposition have been synthesized by a one-pot evaporation-induced self-assembly method. The catalysts were characterized by various techniques including powder X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption, and transmission/scanning electron microscopy (TEM/SEM). Especially, in situ XRD under catalytic reaction conditions was performed, and metallic Co with a cubic structure was identified to be most probably the active crystalline phase for the decomposition of ammonia; also, contribution of CoO to the catalytic activity cannot be excluded. Most importantly, the introduction of alumina can significantly suppress the agglomeration of the active metallic Co phase and thus maintain the high activity of the cobalt catalyst.