An Overview of the Challenges and Progress of Synthesis, Characterization and Applications of Plugged SBA-15 Materials for Heterogeneous Catalysis.

A new generation of SBA-15, plugged SBA-15, was initially synthesized in 2002 using extra silica precursors (Si/organic template molar ratios ≈ 80-140) in the gel mixture. The plugged SBA-15 materials possess short cylinders (length ≈ 20-100 nm), which are connected to neighbors by constricted entrances (windows) through the central axis. The gas adsorption-desorption isotherms of plugged SBA-15 materials present unique hysteresis loop Type H5 classification identified by IUPAC in 2015, which is related to certain pore structures containing open and plugged mesopores.