Application of a Response Surface Method for the Optimization of the Hydrothermal Synthesis of Magnetic NiCo[sub.2]O[sub.4] Desulfurization Catalytic Powders

• Published in: Catalysts Vol. 13; no. 7
• Main Authors: Zhang, Yinke, Li, Lu, Shang, Zihan, Xu, Hang
• Format: Journal Article
• Language: English
• Published: MDPI AG 01.07.2023
• Subjects: Methods; Powders; Tetracycline; Tetracyclines
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal13071119

In this study, nickel cobaltate (NiCo[sub.2]O[sub.4]) powders are employed as a catalyst in conjunction with persulfate for the development of a catalytic oxidation system to enhance fuel desulfurization. The hydrothermal synthesis conditions of NiCo[sub.2]O[sub.4] powders, which significantly influenced the desulfurization efficiency, were optimized using a response surface methodology with a Box–Behnken design. These conditions were ranked in the following order: calcination temperature > hydrothermal temperature > calcination time > hydrothermal time. Through the optimization process, the ideal preparation conditions were determined as follows: a hydrothermal temperature of 143 °C, hydrothermal time of 6.1 h, calcination temperature of 330 °C, and calcination time of 3.7 h. Under these optimized conditions, the predicted desulfurization rate was approximately 85.8%. The experimental results closely matched the prediction, yielding a desulfurization rate of around 84%, with a minimal error of only 2.1%. To characterize the NiCo[sub.2]O[sub.4] powders prepared under the optimal conditions, XRD, SEM, and TEM analyses were conducted. The analysis revealed that the microscopic morphology of NiCo[sub.2]O[sub.4] exhibited a rectangular sheet structure, with an average particle size of 20 nm. Additionally, fan-shaped NiCo[sub.2]O[sub.4] particles were observed as a result of linear and bundle agglomerations. Thus, this work is innovative in its ability to synthesize nano-catalysts using hydrothermal synthesis in a controllable manner and establishing a correlation between the hydrothermal synthesis conditions and catalytic activity.