Adsorption Monitoring of Hydrothermal and Thermal Stability of Polymer-Templated Mesoporous Materials

摘要

The thermal and hydrothermal stability of FDU-1 silica with ordered,large(~ 10 nm),cage-like meso-pores was studied using nitrogen and argon adsorption at - 196deg C.It was confirmed that FDU-1 silica retains uniform mesoporosity even after heating for 5 hours at 950-1000deg C.Although typical FDU-1 silicas and other polymeric-templated silicas with large cage-like mesopores tend to be significantly microporous,the FDU-1 sample calcined at 1000deg C appeared to be essentially free from microporosity,as can be inferred from the relation between its surface area,pore volume and pore diameter.This result suggests that high-temperature calcination can be used to synthesize model mesoporous adsorbents with large cage-like(spherical)mesopores.Evidence of the concomitant decrease in the pore diameter and the pore entrance size with an increase in the calcination temperature is presented.The structural stability of FDU-1 during heating in water at 100deg C for 2,4,and 8 days is additionally demonstrated.