Relation of Selective Oxidation Catalytic Performance to Microenvironment of Ti<sup>IV</sup> Active Site Based on Isotopic Labeling
Hao Xu, Yejun Guan, Xinqing Lu, Jinpeng Yin, Xiaohong Li, Danhong Zhou, Peng Wu
Abstract
The microenvironment of active sites in zeolite framework is critical for catalytic performance. Four Ti-MWW titanosilicates, prepared by different methods in this study, fell into two categories in view of intrinsic catalytic activity in liquid-phase ketone ammoximation and alkene epoxidation reactions. Isotopic labeled IR spectra and DFT calculation disclosed that rather than the traditional 960 cm–1 band, the Ti–O–Si sites dominating an unusual band at 930 cm–1 endowed Ti-MWW with much higher activity.
Topics & Concepts
CatalysisChemistryAlkeneIsotopic labelingZeoliteKetonePhase (matter)Heterogeneous catalysisSpectral lineInorganic chemistryPhotochemistryNuclear chemistryOrganic chemistryPhysicsAstronomyZeolite Catalysis and SynthesisCatalysis and Oxidation ReactionsPolyoxometalates: Synthesis and Applications