One-pot direct synthesis route to self-assembled highly ordered Zn-decorated mesoporous aluminium oxide toward efficient and sustainable metathesis heterogeneous catalyst design

Hexagonally well-organized ZnCl2-OMA materials have been successfully synthesized by a one-pot approach using a sol-gel method at ambient temperature and pressure. These materials were prepared through simultaneous self-assembly process with F127 as directing agent combined with in situ impregnation of ZnCl2. The new approach was found to be compatible with various common aluminium precursors and carboxylic acids used as self-assembly interfacial protectors. The obtained ZnCl2-OMA materials were fully characterized using XRD, N-2 adsorption-desorption, TEM, SEM, EDX, XPS and H-1 and Al-27 MAS-NMR techniques. These materials were compared with the zinc chloride-doped organized mesoporous alumina (ZnCl2-OMA) supports prepared through a conventional two steps process that includes OMA synthesis and then post-synthesis incorporation of ZnCl2. Thus, the one-pot synthesized materials were found to exhibit improved properties compared to the conventional ones, particularly larger BET surface area. The synthesized ZnCl2-OMA materials were then used as catalytic supports for methyltrioxorhenium (MTO), showing enhanced catalytic performance for methyl oleate self-metathesis, demonstrating better activity and selectivity towards desired metathesis products. These features are highly beneficial for large-scale materials synthesis through fast, simple, easy and low-cost introduction of functionalities on mesoporous materials surface without multi-step procedures.