Indexed by:期刊论文
Date of Publication:2016-11-16
Journal:CHEMISTRYSELECT
Included Journals:SCIE
Volume:1
Issue:19
Page Number:6160-6166
ISSN No.:2365-6549
Key Words:heterogeneous catalysis; hollow; nanoparticles; oxidation; post-synthesis; titanium silicalite-1; zeolites
Abstract:A titanium silicalite-1 (TS-1) extrudate with high content of titanium on the external surface was post-synthesized by using the mixed solution of tetrapropylammonium hydroxide and the hydrolysate of tetrabutyl titanate. The influence of Ti concentration in the post-synthesis solution on the physicochemical properties and catalytic performance of TS-1 was also studied. The amorphous silica support covering on the external surface of TS-1 was crystallized, and some hollows appeared in the samples that were post-synthesized. Most titanium introduced by this method are located at the external surface of the new generated TS-1 particles. The molar ratio of Si/Ti on the external surface decreases with the increase of the Ti concentration in the post-synthesis solution. The catalytic activity for phenol hydroxylation over the TS-1 samples is enhanced after the post-synthesis due to the new generated framework Ti on the external surface, providing the reactants more easily adsorbable active centers. A proper Ti concentration (10 vol%) in the post-synthesis solution leads to the highest catalytic activity by obtaining a proper ratio of tetrahedral and octahedral Ti to anatase TiO2.