Selective Photocatalytic Oxidative Ethane Dehydrogenation on AuPd Nanoparticle-Decorated TiO<sub>2</sub>
Xindan Zhang, Jiale Shi, Xiaoyan Wu, Fanxun Lv, Xuan Wang, Shaohua Chen, Yi Yu, Pengxin Liu, Chenlu Xie
Abstract
Photocatalytic oxidative dehydrogenation of ethane offers a promising approach for producing ethylene under mild conditions. However, achieving high ethylene yields and selectivity is challenging due to the high C–H bond activation barrier in ethane and the tendency for overoxidation to CO 2 . In this study, we demonstrate that TiO 2 with highly dispersed AuPd nanoparticles serves as an efficient and selective photocatalyst for the dehydrogenation of ethane with O 2 in a flow reactor. The optimized Au 0.33 Pd 0.67 /TiO 2 achieves up to 20.3 mmol g –1 h –1 of ethylene with 91.5% selectivity, resulting in a 5.9% apparent quantum efficiency at 365 nm. Detailed characterizations reveal that the Au 0.33 Pd 0.67 cocatalyst plays a crucial role in facilitating photocarrier separation and regulating the formation of active oxygen species. Au 0.33 Pd 0.67 effectively activates lattice oxygen of TiO 2, which serves as the localized oxidant to promote ethane dissociation through a photoassisted Mars-van Krevelen mechanism. Additionally, Au 0.33 Pd 0.67 /TiO 2 facilitates dioxygen reduction and ensures rapid oxygen replenishment in the TiO 2 lattice, thereby achieving a high yield of ethylene formation. This work provides valuable insights for designing composite photocatalysts for efficient and selective ethane oxidative dehydrogenation.