APPROACH TO PHOTOCATALYSIS AT THE MOLECULAR LEVEL - DESIGN OF PHOTOCATALYSTS, DETECTION OF INTERMEDIATE SPECIES, AND REACTION MECHANISMS

摘要

The characterization of the Cu+/ZSM-5 catalysts prepared via seduction of ion-exchanged Cu2+/ZSM-5 samples and highly dispersed Ti-oxide catalysts anchored on Vycor glass has been undertaken by in-situ photoluminescence, EPR, XAFS (XANES and FT-EXAFS), and FT-IR spectroscopy. UV-irradiation of the Cu+/ZSM-5 catalyst in the presence of NO leads to the direct photocatalytic decomposition of NO into N-2 and O-2 at normal temperatures. UV-irradiation of the highly dispersed anchored Ti-oxide catalyst in the presence of CO2 and H2O also leads to the evolution of CH4, CO, and CH3OH at normal temperatures. The clarification of the coordination structure of the active surface sites and the direct detection of the reaction precursors and intermediate species in these photocatalytic systems contributed significantly in characterizing the molecular scale reaction mechanisms. Based on these results, the design of highly concentrated and efficient photocatalysts has successfully been achieved by application of the sol-gel method. [References: 22]