Photocatalytic non-oxidative dehydrogenation of ethane to ethene with near unit selectivity

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-Ni_0.6Pd_0.24 photocatalyst. Solar-driven non-oxidative alkane dehydrogenation offers a route to light alkenes with high performance, and selectivity.