Synthesis of zirconia porous phosphate heterostructures (Zr-PPH) for Prins condensation
•Zirconia PPH material was synthetized by co-templated method.•The sample prepared in propanol has higher surface area and acidity than in water.•Zr-PPH materials showed good catalytic activity in the Prins condensation.•Lewis acid sites play an important role in selective synthesis of Nopol.
Porous phosphate heterostructure materials with zirconia galleries have been prepared. Their acid properties were studied via 2,6-di-tert-butyl-pyridine adsorption, infrared spectra of pyridine adsorption and potentiometric titration. The samples prepared in alcohol media are more thermal stable than those prepared in aqueous media. They are very active and selective for the Prins condensation of β-pinene with paraformaldehyde because of large amount of Lewis acid sites as well as proper L/B ratio. The selectivity towards Nopol can be further improved by ion-exchanging with sodium cations, due to the elimination of Brønsted acid sites which suppresses the by-reactions such as isomerization of β-pinene.
Journal: Catalysis Communications - Volume 43, 5 January 2014, Pages 97–101