Engineering sodium-decorated bifunctional Au-Ti sites to boost molecular transfer for propene epoxidation with H2 and O2

Regulating the microenvironment of active sites is crucial to boost the performance of direct propene epoxidation with H 2 and O 2 . Herein, the enhanced surface transfer of H 2 O 2 intermediates was first achieved by sodium-decorated Au-Ti bifunctional active sites. Combined with multi-techniques (e.g., operando UV–vis–NIR system, DFT studies and quantitative model calculations), it is found that the sodium-decorated silanols (Si-ONa species) on the TS-1 support enhance the formation of Ti-OOH intermediates by restraining H 2 O 2 decomposition. In addition, sodium-decorated silanols improves the desorption of propylene oxide, suppressing its ring-opening and formation for the carbonaceous deposits. Moreover, the sodium-decorated Au nanoparticles with smaller diameter and higher electron density further strengthen O 2 adsorption and boost the H 2 O 2 formation. This work not only provides fundamental understandings on the microenvironment of Au-Ti bifunctional catalysts but also sheds new light on enhancing the performance by boosting the surface molecular transfer.