Bimetallic Au-Pd NPs with a mean particle size of ca. 1.7 nm were prepared by colloidal synthesis with PVA as a stabilizer and immobilized on various ceria and titania nanostructures. The catalysts were characterised by TEM, XRD, XPS, ICP-AES, and their catalytic performance assessed in the solvent-less selective oxidation of benzyl alcohol. It is shown that even with a technique such as sol-immobilization, the final particle size is sensitive to the physiochemical properties and morphology of the support. In particular, ceria nanostructures were found to be more effective at stabilizing colloidal Au-Pd NPs than titania. Among the ceria nanostructured supports investigated, Au-Pd/ceria nanorods exhibited the highest catalytic activity (TOF > 34,700 h−1) and highest benzaldehyde yield. The particle size of the supported Au-Pd was found to be correlated with the surface area and concentration of Ce3+ and oxygen vacancies in the ceria nanostructures. Overall, the catalytic activity of supported bimetallic Au-Pd catalysts is likely to be governed by a complex interplay of contributions from the particle size, and support morphology, structure and properties.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Aug 28 2020|
Bibliographical noteKAUST Repository Item: Exported on 2021-07-13
Acknowledgements: Motaz Khawaji gratefully acknowledges the financial support of Saudi Aramco. This work was funded in part by Saudi Aramco and EPSRC (EP/K014749/1). We are grateful to Dr. Ecaterina Ware for her assistance with TEM.