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

摘要

Zirconium was incorporated into ultra large pore mesoporous silicate, KIT-6, for the first time via hydro-thermal synthesis using a Pluronic PI 23 triblock copolymer as the structure directing agent and n-buta-nol as additive. Various characterization tools such as XRD, elemental analysis, N2 sorption, HR-TEM, ~(29)Si 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 m~2/g with pore volume of ~1.1 cm~3/g. An average pore size of about 9 nra 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.