Radiolytic approach for efficient, selective and catalyst‐free CO2 conversion at room temperature

Changjiang Hu (1) , Sarah Al Gharib (2) , Yunlong Wang (1) , Pingping Gan (1) , Qiuhao Li (1) , Sergey A Denisov (2) , Sophie Le Caër (3) , Jacqueline Belloni (2) , Jun Ma (1) , Mehran Mostafavi (2)

1 NUAA - Nanjing University of Aeronautics and Astronautics [Nanjing]
2 ICP - Institut de Chimie Physique
3 LIONS - Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire

The present study proposes a new approach for direct CO$_2$ conversion using primary radicals from water irradiation. In order to ensure reduction of CO$_2$ into CO$_2^{-•}$ by all the hydrated electrons, we use formate ions to scavenge simultaneously the parent oxidizing radicals H$^•$ and OH$^•$ producing the same transient CO$_2^{-•}$ radicals. Conditions are optimized to obtain the highest conversion yield of CO$_2$. The goal is achieved under mild conditions of room temperature, neutral pH and 1 atm of CO$_2$ pressure. All the available radicals are exploited for selectively converting CO$_2$ into oxalate that is accompanied by H$_2$ evolution. The mechanism presented accounts for the results and also sheds light on the data in the literature. The radiolytic approach is a mild and scalable route of direct CO$_2$ capture at the source in industry and the products, oxalate salt and H$_2$, can be easily separated.

Domains: Material chemistry; Theoretical and/or physical chemistry

Changjiang Hu, Sarah Al Gharib, Yunlong Wang, Pingping Gan, Qiuhao Li, et al.. Radiolytic approach for efficient, selective and catalyst‐free CO2 conversion at room temperature. ChemPhysChem, 2021, 22 (18), pp.1900-1906. ⟨10.1002/cphc.202100378⟩. ⟨cea-03287511⟩