Boehmite nanoparticles as versatile support for organic–inorganic hybrid materials: Synthesis, functionalization, and applications in eco-friendly catalysis

Alpha and gamma-alumina are materials used as continuous coatings and also in various fields such as ceramics, catalysis and catalytic support, lubricants, and electronics. Boehmite (AlOOH) is used as the raw material for the preparation of alpha and gamma-alumina phases whose properties such as morphology, specific surface area, and porosity, are strongly dependent on the boehmite structure. In this review, various methods for synthesizing boehmite nanoparticles (NPs); including, sol–gel, sedimentation, sewage, and hydrothermal have been reviewed. The most appropriate method for the production of various forms of boehmite is the hydrothermal method. The shape, morphology, and tissue properties of the boehmite NPs depend heavily on the conditions of the process, i.e. the pH of the solution, the temperature, and the reaction time which will be described in this review. Moreover, the application of boehmite as the catalyst or catalytic support is studied in this review. Therefore, metallic, acidic, basic, ionic, organic, and organometallic catalysts, which are immobilized on boehmite NPs are discussed in this review.