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

摘要

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 N_2 at 1,450 ℃. Small-angle XRD, SEM/TEM, ~(29)Si and ~(27)A1 MAS-NMR and BET specific surface area measurements of the Al-SBA-15 and P4VP/A1-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 ~(29)Si-NMR. Firing the nanocomposite in a N_2 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.