Abstract
To estimate the positions of Brönsted acid sites on ITQ-21 containing Al atoms (Al-ITQ-21), the physicochemical and catalytic properties of Al-ITQ-21 as a solid acid catalyst were investigated. The multinuclear solid-state nuclear magnetic resonance (MAS NMR) spectra of 27Al and 1H of Al-ITQ-21 having several concentration of Al were measured, along with the NH3 temperature programmed desorption spectra, while the conversion of n-heptane was examined over Al-ITQ-21 having several concentrations of Al. The positions of the Al atoms in the Al-ITQ-21 lattice were limited by measuring 27Al MAS NMR spectra. This limitation made the designation of oxygen atoms bonded to acidic protons identify by measuring both spectra of the NH3 temperature programmed desorption and 1H MAS NMR. Furthermore, the total reaction rates for the conversion of n-heptane on different Brönsted acid sites were determined.