Photocatalytic non-oxidative dehydrogenation of ethane to ethene with near unit selectivity
Xiaoyu Sui, Jiwu Zhao, Pu Zhang, Ying Wang, Hangbin Zheng, Haihua Zeng, Pengzhao Wang, Yanyan Jia, Na Wen, Zhengxin Ding, Zizhong Zhang, Sheng Dai, Chao Xu, Rusheng Yuan, Wenxin Dai, Xianzhi Fu, Jinlin Long
Abstract
The non-oxidative dehydrogenation of light alkanes to alkenes is thermodynamically limited by the trade-off between the cleavage of C-H and C-C bonds. Unlocking the thermodynamic bottleneck with photocatalysis is prone to eliminate undesirable side reactions such as deep dehydrogenation, cracking, isomerization, and polymerization. Herein, we show the photocatalytic non-oxidative dehydrogenation of ethane to ethene and hydrogen at ambient conditions, which is enabled by grafting of Ni single atoms to modulate the surface electronic structure of Pd nanoparticles photo-deposited on the surface of anatase TiO2 nanoparticles, modifying the ethane dehydrogenation pathway. A high rate of 8.2 ± 0.2 mmol·g−1·h−1 for the stoichiometric conversion of ethane to ethene and hydrogen is achieved with a 100% ethene selectivity in a flow reactor under solar light irradiation. The apparent quantum efficiency reaches ~22.3% at 350 nm by using the optimal T-Ni0.6Pd0.24 photocatalyst. Solar-driven non-oxidative alkane dehydrogenation offers a route to light alkenes with high performance, and selectivity. Non-oxidative alkene dehydrogenation is hindered by side reactions like cracking, iso- or polymerization, or alkyne formation. Here the authors report a Pd/TiO2 photocatalyst decorated with Ni single sites for selective ethane to ethylene production under simulated solar light conditions with high yields.