In situ XAFS studies on the effects of the hydrophobic-hydrophilic properties of Ti-Beta zeolites in the photocatalytic reduction of CO2 with H2O

The photocatalytic reduction of CO2 with H2O to produce CH4 and CH3OH was found to proceed in the gas phase at 323 K with different reactivities and selectivities on hydrophilic Ti-Beta(OH) and hydrophobic Ti-Beta(F) zeolites prepared in the OH- and F- media, respectively. In situ XAFS measurements have revealed that these differences are attributed to the differences in the affinity for the adsorption of H2O molecules on the highly dispersed tetrahedrally coordinated titanium oxide species depending on the hydrophobic-hydrophilic properties of zeolites.