Complex hydrides for CO2 reduction

Fossil fuels consumption is not expected to decrease significantly in the next decade, driving the atmospheric carbon dioxide concentration upward. Tremendous efforts have been made in the field of carbon capture with the development of porous material adsorbents such as metal-organic frameworks. New thermal and electrochemical catalytic processes have also been established to reduce CO2 into valuable products such as formic acid, ethanol, or hydrocarbons. Combining the CO2 capture and transformation in a single process is a clever way to optimize the overall process. Complex hydrides such as borohydrides (MBH4, M=Na, Li, ...) and alanates (MAlH4) are frequently used as reducing agents in chemistry. They are also known as potential solid-state hydrogen storage materials. The superior gravimetric hydride density confers to these materials appealing properties for CO2 reduction. This article summarizes the reactivity of complex hydrides, especially borohydrides, with CO2, as well as the recent development in this field.