We have studied the changes in the adsorption characteristics of mesoporous silicate (SBA-15) for benzene and toluene that are caused by using different calcination temperatures (Tc = 773 to 1173 K) in the synthesis process. We found that SBA-15 calcined at 773 K shows an extremely high benzene selectivity, especially in the low pressure region, while SBA-15 treated at higher Tc shows lower selectivity. In order to analyze the benzene selective mechanism, we studied the structures of the SBA-15 series, including their meso- and microporosity in detail. We found that the BET surface area (SBET) and the peak position of the mesopore diameter (2R p) decreased, the peak position of the micropore diameter (2r p) increased, and the 2rp distribution became broader with increasing Tc. Among above factors, we conclude that the size and the distribution of 2rp are the most important to achieve a high benzene selectivity.
ASJC Scopus subject areas
- Materials Chemistry