Suppressing COx in oxidative dehydrogenation of propane with dual-atom catalysts
Yongbin Yao, Jingnan Wang, Fei Lu, Wenlin Li, Bingbao Mei, Lifeng Zhang, Wensheng Yan, Fangli Yuan, Guiyuan Jiang, Sanjaya D. Senanayake, Xi Wang
Abstract
Oxidative dehydrogenation of propane (ODHP) is a promising route for propylene production, but achieving high selectivity towards propylene while minimizing COx byproducts remains a significant challenge for conventional metal oxide catalysts. Here we propose a solution to this challenge by employing atomically dispersed dual-atom catalysts (M1M'1-TiO2 DACs). Ni1Fe1-TiO2 DACs exhibit an ultralow COx selectivity of 5.2% at a high propane conversion of 46.1% and 520 °C, with stable performance for over 1000 hours. Mechanistic investigations reveal that these catalysts operate via a cooperative Langmuir-Hinshelwood mechanism, distinct from the Mars-van Krevelen mechanism typical of metal oxides. This cooperative pathway facilitates efficient conversion of propane and oxygen into propylene at the dual-atom interface. The superior selectivity arises from facile olefin desorption from the dual-atom sites and suppressed formation of electrophilic oxygen species, which are preferentially adsorbed on Fe1 sites rather than oxygen vacancies. This work highlights the potential of dual-atom catalysts for highly selective ODHP and provides insights into their unique catalytic mechanism. Propane oxidative dehydrogenation offers a promising path for propylene production, but selective propylene formation with minimal COx remains challenging. Here, the authors introduce dual-atom catalysts achieving just 5.2% COx selectivity at 46.1% propane conversion (520 °C) with stable performance for over 1000 hours.