Reversible Hydrogenation of CO<sub>2</sub> to Formamides Using an Atomically Dispersed Ir/C<sub>3</sub>N<sub>4</sub> Catalyst
Danyang Cheng, Maolin Wang, Maolin Wang, Shixiang Yu, Mi Peng, Wu Zhou, Wulin Yang, Meng Wang, Meng Wang, Ding Ma
Abstract
The utilization of different energy carriers to efficiently store and release energy plays a vital role in the pursuit of a renewable energy paradigm. In this context, we present an interesting system utilizing morpholine as a dual-functional agent in the reversible hydrogenation of CO 2 to formamides employing an atomically dispersed iridium (Ir) catalyst. Morpholine serves as a stabilizer during CO 2 hydrogenation and a CO 2 capture agent during dehydrogenation, enabling a carbon-neutral cycle for hydrogen storage. Notably, these reversible cycles could be facilitated by the same catalyst and maintained under identical temperature conditions by a simple H 2 pressure swing. The robustness of this system is underscored by its consistent performance across multiple charging–discharging cycles without a noticeable reduction in the storage capacity. Additionally, the Ir catalyst exhibits strong CO tolerance during hydrogenation, making it suitable for purifying crude hydrogen via the reversible process.