Synthesis and characterization of Zirconium incorporated ultra large pore mesoporous silicate, Zr–KIT-6

Zirconium was incorporated into ultra large pore mesoporous silicate, KIT-6, for the first time via hydrothermal synthesis using a Pluronic P123 triblock copolymer as the structure directing agent and n-butanol as additive. Various characterization tools such as XRD, elemental analysis, N2 sorption, HR-TEM, 29Si MAS NMR, DR-UV–Vis and NH3-TPD were employed to understand the morphology, textural properties, structure and the nature of Zirconium coordination. The Zr–KIT-6 samples possess a very high specific surface area of ∼740 m2/g with pore volume of ∼1.1 cm3/g. An average pore size of about 9 nm is evident from N2 sorption and HR-TEM studies. Even though the majority of Zr is incorporated in the silicate framework, highly dispersed ZrO2 nanoparticles are evident in all the samples. The Zr–KIT-6 is also shown to possess acid sites of medium strength.

Graphical abstractZirconium incorporated large pore ordered mesoporous silicate, Zr–KIT-6, was prepared using one-step hydrothermal synthesis. Lewis acidity of Zr–KIT-6 is due to uniformly distributed framework substituted Zr4+ sites.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Zr-incorporated ordered mesoporous silicate, Zr–KIT-6, with ∼9 nm pores synthesized. ► Zr–KIT-6 samples possess high surface area (∼740 m2/g) and pore volume (∼1.1 cm3/g). ► Highly dispersed ZrO2 nanoparticles evident at all Zr loadings. ► Lewis acidity of Zr–KIT-6 is due to highly distributed framework substituted Zr4+ sites.