Multi-level three-dimensional Mg–Al layered double hydroxide hierarchical microstructures with enhanced basic catalytic property

• Published in: Journal of colloid and interface science Vol. 432; no. 432; pp. 1 - 9
• Main Authors: Yu, Jiaying, Fan, Guoli, Yang, Yang, Li, Feng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 15.10.2014; Elsevier
• Subjects: Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Layered double hydroxide; Morphosynthesis; Multi-level superstructure; Solid base catalysts; Surfactant; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Multi-level superstructure; Surfactant; Layered double hydroxide; Morphosynthesis; Solid base catalysts; Solid base catalyst; Catalytic reaction; Superstructure; Microstructure
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2014.06.054

[Display omitted] •Rosette-like MgAl–CO3-LDH microstructures are synthesized via surfactant-assisted route.•Possible formation mechanism for flower-like micro-nanostructure is proposed.•Activated MgAl-LDH possesses multi-level hierarchical superstructure.•Activated flower-like MgAl-LDH showed enhanced basic catalytic activity. Novel three-dimensional (3D) rosette-like carbonate-type Mg–Al layered double hydroxide (MgAl-LDH) hierarchical microstructures were fabricated successfully by a surfactant-assisted coprecipitation method in the presence of hexamethylenetetramine as precipitant, and the morphology-dependent basic catalytic property was exploited. The morphologies of MgAl-LDH aggregates were diversified depending on the synthesis parameters including the type of precipitant, concentration of sodium stearate surfactant, and hydrothermal aging time. Specifically, the morphology of MgAl-LDH particles could change progressively from platelet-like aggregates to rosette-like microspheres with the increasing concentration of sodium stearate. A possible formation mechanism for special 3D flower-like MgAl-LDH microstructures was proposed based on the synergistic effect of precipitant with surfactant. Moreover, the resulting activated rosette-like MgAl-LDH, which was prepared through calcination–rehydration process, showed a higher catalytic activity in the transesterification of tributyrin with methanol, compared with that derived from the conventional platelet-like MgAl-LDH precursor, which was attributed to its higher specific basicity originating from multi-level hierarchical superstructure offering an advantage in contact with more exposed base sites.