Soft-to-hard consecutive templating one-pot route from metal nitrate/phenol resin/surfactant to mesoporous metal oxides with enhanced thermal stability

摘要

Mesoporous materials with crystalline ZrO2, Y2O3, and CeO2 frameworks were one-pot synthesized from a clear solution of ethanol containing metal nitrates, organic surfactant (i.e., Pluronic (R) F-127), formaldehyde, and phloroglucinol. The solution was converted to a mesostructured nanocomposite of metal nitrate/phenol resin/ surfactant via a solvent evaporation-induced self-assembly process. The obtained nanocomposite was calcined at 800 degrees C in a N-2 atmosphere. X-ray powder diffraction and electron microscopic investigation revealed that the calcination caused amorphous-to-crystalline transformations in the metal oxide frameworks, while sintering to bulk metal oxides was prevented by the in-situ generated carbon component. Mesoporous metal oxides with a crystalline framework were obtained when the carbon skeleton was burnt off. The mesoporous metal oxides exhibited high BET surface areas, narrow pore-size distributions, and enhanced thermal stability. A practical benefit of the mesoporous metal oxides was demonstrated with Au/CeO2 exhibiting high catalytic activity in the water-gas-shift reaction.