Superalkalis for the Activation of Carbon Dioxide: A Review

Abstract

The activation of carbon dioxide is essential not only for global carbon balance but also for its conversion into fuel. As CO2 is highly stable, it is quite challenging to activate or reduce CO2. Recently, the ability of superalkalis to easily transfer an electron to CO2 has been proposed in several studies. The superalkalis are species possessing lower ionization energy than alkali atoms. These are hypervalent species, having an excess of electrons. Owing to this, they possess strong reducing power and cause the linear structure of CO2 to bend by transferring an electron to it. Herein, we present a comprehensive account of the single-electron reduction and activation of CO2 by various kinds of superalkalis. This review also includes a novel strategy for the capture and storage of CO2 by superalkali.

Recent advances in in silico design and characterization of superalkali-based materials and their potential applications: A review

“…As CO 2 , with the property of trapping greenhouse gases, has a crucial role in the global carbon balance purpose along with its conversion into fuel, a very recent in silico -based report by H. Srivastava and A. K. Srivastava on the activation of CO 2 by various types of superalkalis can be seen in the literature where they showed comprehensive and interesting theoretical outcomes (see Figure 4C ) ( Srivastava and Srivastava, 2022 ). Some studies on the superbases which were designed with the help of superalkalis can be seen in the literature ( Srivastava and Misra, 2015 , Srivastava and Misra, 2016 ).…”

Interaction of N2, O2 and H2 Molecules with Superalkalis

“…More importantly, it can be used for the reduction of the CO 2 molecule which possesses no positive electron affinity. [28][29][30][31] Nitrogen (N 2 ) is earth's most prevalent gas molecule whose inertness makes it impossible to employ directly for metabolism. [32] Its high ionization energy (15 eV) and its inability to attach an extra electron provide formidable obstacles to its oxidation and reduction, respectively.…”

“…Reportedly, the superalkali species are employed to activate small molecules such as carbon monoxide, [25] dinitrogen (N 2 ), [26] NO x , [27] etc. More importantly, it can be used for the reduction of the CO 2 molecule which possesses no positive electron affinity [28–31] …”

“…More importantly, it can be used for the reduction of the CO 2 molecule which possesses no positive electron affinity. [ 28 , 29 , 30 , 31 ]…”