Propylene oxide (PO) is an important chemical intermediate for producing a variety of useful polymeric materials. Direct propylene epoxidation in the presence of H2 and O2 has many advantages compared with existing chlorohydrin, hydroperoxide and hydrogen peroxide process. In this reaction, the synergy between supported gold nanoparticles and isolated titanium sites are essential. High selectivity (&gt;90%) has been achieved by using this strategy. However, the gold-TiO2 based catalysts still suffer from low conversion and poor stability. A well-define catalysts system would possibly bring new insight to understand the reaction kinetics and improve the conversion and stability. Atomic layer deposition (ALD) enables conformal deposition of nanoparticles and thin films with atomic precision. The loading and morphology of TiO2 can be precisely controlled by choosing proper cycle and sequence of TiO2 ALD. The oxidation state and coordination of both Au and TiO2 can be monitored under reaction conditions in real time. In this work, we will highlight the combination of precise catalyst synthesis and in situ synchrotron X-ray characterizations under typical propylene epoxidation conditions to establish precise structure-performance relationship.

Effects of TiO2 in low temperature propylene epoxidation using Au/SiO2 catalysts

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.