Synergistic effect of Zr-incorporated framework and subsequent deposition of PEHA towards efficient and reusable HPW/PEHA/ZrSBA-15 composites

Heteropolyacid-based catalysts with molecular level distributions of surface functionalities were synthesized by anchoring phosphotungstic acid (HPW) onto the pentaethylenehexamine (PEHA) layers stabilized by platelet ZrSBA-15 with short mesochannels. Namely, the presence of zirconium species in pore walls could significantly improve the surface acidity to attract and stabilize PEHA species, leading to a stronger interaction between them and a superiority to make HPW species highly stable. Standard characterizations of XRD, SEM, TEM, FT-IR, TG, N2 adsorption–desorption and N elemental analyses were preserved to demonstrate the synergistic effect. The resulting composite were investigated for the oxidation of benzaldehyde to benzoic acid in the H2O2-mediated environment, the catalyst 25 % HPW/PEHA/ZrSBA-15 screened high yield for benzoic acid (~99.7 %). Besides, various reaction parameters such as reaction temperature, reaction time, the amount of hydrogen peroxide and catalyst reusability were also investigated for the oxidation of benzaldehyde to benzoic acid with a target to confirm the validity of the catalyst.