CRN synthesis of β-SiAlON from a nanocomposite precursor of mesoporous silica–alumina (Al-SBA-15) with poly 4-vinyl pyridine

This paper reports the use of a nanocomposite precursor of mesoporous silica–alumina (Al-SBA-15) with poly 4-vinyl pyridine (P4VP) to synthesise β-SiAlON by carbothermal reduction and nitridation under N2 at 1,450 °C. Small-angle XRD, SEM/TEM, 29Si and 27Al MAS-NMR and BET specific surface area measurements of the Al-SBA-15 and P4VP/Al-SBA-15 composite confirmed the mesoporous structure and the presence of Al in the precursors, while surface polymerization of the Al-SBA-15 was indicated by 29Si-NMR. Firing the nanocomposite in a N2 atmosphere forms the nitride phase, depending on the amount and type of carbon present, on the surface area of the precursor. Even with these precursors of high surface area, the present result was obtained using approximately twice the stochiometric amount of carbon.