Ag-CeO2/SBA-15 composite prepared from Pluronic P123@SBA-15 hybrid as catalyst for room-temperature reduction of 4-nitrophenol

摘要

The catalytic activity of the SBA-15-supported silver and/or ceria catalysts in the 4-nitrophenol reduction under mild conditions is described. The catalysts are prepared by wetness impregnation of Pluronic P123@SBA-15 hybrid applied to stabilize small Ag and CeO2 particles. The bare SBA-15 and the catalysts on the basis thereof are characterized by N-2 sorption, XRD, SAXS, TEM, UV-vis DRS, and H-2-TPR. The catalysts possess high surface area (594-754 m(2)/g) and narrow pore size distributions (5.5-7.8 nm). Silver and ceria particles are stabilized in a highly dispersed state (predominant sizes below 5 nm) in the ordered SBA-15 structure. The Ag-CeO2/SBA-15 catalyst demonstrates the presence of the developed Ag-CeO2 interface that enhances the catalytic activity in 4-nitrophenol reduction to 4-aminophenol (k = 0.016 s(-1)) at room temperature and ambient pressure due to the cooperation of silver and ceria active sites.