MOF-74 derivatives spinel CuCo2O4/C with d-band center modulation for accelerating ammonium perchlorate thermolysis

• Published in: Fuel (Guildford) Vol. 370; p. 131814
• Main Authors: Wei, Shilong, Tan, Hanjie, Zhang, Yifan, Xia, Zhengqiang, Yang, Qi, Xie, Gang, Chen, Sanping
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-08-2024
• Subjects: AP combustion catalysts; Cobalt-based spinel structure; Cu–O-Co interaction; D-band center; D-band center; Cobalt-based spinel structure; Cu–O-Co interaction; AP combustion catalysts
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2024.131814

•MOF-74-CoCu as specific precursor pyrolysis-produces highly active spinel structure supported on carbon CuCo2O4/C.•Electron transferring through the CuTd-O-CoOh from CoOh to CuTd and d-band central theory co-confirms high NH3 adsorption on CuCo2O4/C.•The THDS of CuCo2O4/C at 295.7℃ is lower by 161.2 ℃ than pure AP.
As one of main components of solid propellant, ammonium perchlorate (AP) shows slow sluggish decomposition kinetics with unconcentrated heat release. In the past, researchers have done a lot of work using spinel oxides as combustion modifiers to improve the combustion performance of AP. However, AP decomposition process is very complicated, and the relationship between intrinsic activity of cobalt-based spinel catalysts and AP combustion process is still unclear. In this paper, a series of cobalt-based spinel structure catalysts, MCo2O4/C, were prepared by pyrolysis of cobalt-containing bimetal MOF-74 and used as AP combustion catalysts. All of them showed excellent catalytic performance, among which CuCo2O4/C had the best catalytic activity. It effectively reduces the activation energy of the reaction, speeds up the reaction rate, and reduces the peak temperature of the AP decomposition reaction by 161.2 ℃, and the reaction rate k is 10.28 times of Co3O4/C. XPS and NH3-TPD tests indicate that substitution CoTd2+ with Cu2+ increases the ratio of Co3+/Co2+ and enhance interaction between NH3 and catalyst. The essential reason is that Cu–O-Co corner sharing effect changes electron distribution and enhances CoOh3+ Lewis acidity accompanied with the proximity of d-band center to EF by density functional theory calculations.