Chemisorption sites for ammonia on fluorinated porous silica glass

Fluorination of porous silica glass led to an increase in the number of adsorption sites which coordinate ammonia. Evacuation of fluorinated and unfluorinated glass at temperatures of approximately 650 °C for 2–3 hr produced a surface which coordinated ammonia molecules, with little evidence of their dissociation. Other studies have shown that after evacuation under more severe conditions, silica glass adsorbed ammonia with much dissociation and with the production of primary and secondary amine radicals.