Nitrogen Loss and Structural Change of Nitrogen-incorporated SBA-15 Mesoporous Materials Under Different Treatment Conditions

Work on nitrogen loss and structural change of nitrogen-containing SBA-15 mesoporous materials after heat treatment in air or water treatment is described herein. The nitrogen-containing SBA-15 lost nitrogen after being treated in air at high temperature or in water, the mesoporous structure of which was very well maintained and did not collapse. HRTEM, N₂ sorption, powder XRD, and SEM were used to study the structural ordering and morphology of the mesoporous silicon oxynitride materials before and after treatment. FTIR and C/N/H elemental analysis confirmed that nitrogen loss occurred after the mesoporous silicon oxynitride material was treated. Nitrogen was lost via hydrolysis of ammonium groups when mesoporous silicon oxynitride material was treated in water and by being substituted by oxygen from air when it was heated in air at high temperature.