Surfactant-free synthesis of sub-10 nm Co3O4 in a rotating packed bed and its high catalytic activity for AP pyrolysis. (15th March 2022)

• Record Type: Journal Article
• Authors: Cao, Shao-Bo; Zhou, Lin-Yu; Xiang, Guolei; Chu, Guang-Wen; Zhang, Liang-Liang; Chen, Jian-Feng
• Is Part Of: Chemical engineering science. Volume 250(2022)
• Publication Date: 2022-03-15
• Subjects: Micro-mixing intensification -- Co3O4 -- Ammonium perchlorate -- Density functional theory; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2021.117391
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Sub-10 nm Co3 O4 is synthesized by surfactant-free precipitation in RPB reactor. The size of Co3 O4 nanoparticle is inherited from the thickness of precursory Co(OH)2 . Sub-10 nm Co3 O4 shows the best catalytic performance for AP decomposition. Size effect of Co3 O4 in AP decomposition has been studied experimentally and theoretically. Abstract: Sub-10 nm Co3 O4 nanoparticles with a narrow size distribution are prepared by a surfactant-free liquid precipitation method in a rotating packed bed (RPB) reactor. The mean size of the material is about 8.5 nm, and is the smallest among previous reports via surfactant-free liquid precipitation. The growth mechanisms show that the sizes of Co3 O4 nanoparticles inherit from the precursory Co(OH)2 . Compared to the traditional stirred tank reactor, RPB can enhance the nucleation of Co(OH)2 through enhanced micro-mixing, which leads to thinner and more uniform products. As-prepared Co3 O4 can show enhanced catalytic performance for ammonium perchlorate (AP) decomposition. The peak temperatures of AP decomposition reduce to 296.8 °C, 291.8 °C, 290.0 °C, and 286.6 °C by adding 2 wt% 22.6 nm, 15.0 nm, 10.9 nm, and 8.5 nm of Co3 O4 nanoparticles, respectively. Density functional theory (DFT) calculations and thermogravimetry coupled with mass spectrometry (TG-MS) analysis reveal that the size-dependent catalytic activity of Co3 O4 for AP decomposition origin from varied O2 activation ability and NH3 adsorption capacity at the edge and corner sites.