One-pot synthesis and characterization of a dual-function hierarchical multiporous composite H3PW12O40@HKUST-1/γ-Al2O3 with enhanced performance in adsorptive desulfurization and acid catalysis

A hierarchical multiporous ternary composite HPW@HKUST-1/γ-Al2O3 (HPW = phosphotungstic acid) is prepared, in which the nanosized HPW@HKUST-1 is formed on both the external and internal surface of mesoporous γ-Al2O3 beads due to the confinement effect of internal pores/channels of the γ-Al2O3 beads. The composite not only possesses excellent adsorptive desulfurization capacity (e.g. 65.3 mg S/g MOF for dibenzothiophene; the adsorption capacities decreased in the order of dibenzothiophene > benzothiophene > 3-methylthiophene > 4,6-dimethyldibenzothiophene) superior to HKUST-1/γ-Al2O3 beads due to the significant role of the favorable acid-base interaction between acidic HPW and slightly basic sulfur-containing compounds, but also exhibits super acid catalytic activity for hydrolysis of ethyl acetate (325.6 mmol molacid −1 min−1) and for synthesis of ethyl acetate (75.4 mol molacid −1 min−1) and n-butyl acetate (13.2 mol molacid −1 min−1) with selectivity of 100%, due to high dispersion and free access of the HPW in the composite which features high surface area and more easily accessible active sites of HPW and HKUST-1. Besides, the composite features remarkable mechanical strength, chemical/thermal stability, being friendly to the environment, and low cost, can easily be regenerated and reused many times for both acid catalysis reactions and adsorptive desulfurization without observable HPW leaching or material dissolution/decomposition.