Microwave‐assisted pyrolysis of organometallic gel prepared through ternary combination of surfactants for fabrication of nano‐porous gamma alumina: adsorptive properties, characterization

Abstract

AbstractBACKGROUNDIn present work, γ‐Al2O3 nanoparticles, with uniform morphology and controllable size, were successfully fabricated by the microwave‐assisted pyrolysis of organometallic gels prepared through the application of aluminum nitrite, urea, glycine, and triple mixed surfactants. A series of pyrolysis reactions were carried out by the conventional and microwave treatments to achieve nano‐porous powders. The effects of different process factors, such as fuel composition, pyrolysis method, calcination temperature, and surfactant mixing ratio, on the adsorptive properties and physico‐chemical characteristics of powders were investigated.RESULTSγ‐Al2O3 nanoparticles (10–20 nm) were successfully synthesized through optimized process variables. Although the calcination temperature is a significant variable in altering adsorptive properties, microwave pyrolysis causes a reduction in the calcination temperature (700 °C). Cetyl trimethyl ammonium bromide (CTAB), which is a cationic surfactant, mixed with a non‐ionic surfactant (Triton‐X‐100) can produce nano‐sized γ‐Al2O3 particles. The stoichiometric aluminum nitrate‐urea admixed with surfactants produced a powder with higher specific surface area, 238 m2 g−1, which is comparable with that obtained via the salt‐urea‐glycine system.CONCLUSIONThough mesoporous powder with a large surface area can be synthesized by urea‐glycine system, the employment of triple surfactant system admixed with urea may be a reliable route to produce mesoporous powder economically. © 2020 Society of Chemical Industry