The trade-off between carbon-based materials and efficient CO2 utilization: Catalytic advances towards cycloaddition of CO2 with epoxides to cyclic carbonates

In colossal effort to reduce global carbon footprint, the efficient utilization of excess amount of greenhouse CO2 gas to produce value-added chemicals such as cyclic carbonates have proven to be a well-designed scientific solution toward emerging sustainability issues. To reduce the global carbon footprint, this protocol utilizes an excess amount of atmospheric greenhouse CO2 gas and produces fine chemicals of both commercial and industrial interest. Nanostructured carbon-based catalysts (NCCs) have emerged as a significant focus in recent years for CO2 conversion due to their effectiveness and unique properties. This review article delves into the development and utilization of NCCs as a trending new class of heterogeneous catalysts for cycloaddition of CO2 with epoxides, highlighting their potential in addressing sustainability challenge. Along with their synthetic methodology, structural features, and measures of catalytically active sites for the effective use of CO2 as a valuable feedstock via specific insertion into epoxides have been discussed. The manuscript begins with an explanation of the structural formation of nanostructured carbon-based materials and their use in the cycloaddition of CO2 into epoxides, detailing the mechanistic pathway. It then broadly reviews NCCs for cycloaddition of CO2 with epoxides, including N-doped porous carbons, graphene and its derivatives, carbon nanotubes, graphitic carbon nitride (g-C3N4), and bio-based or waste-derived carbons from direct and modified pyrolysis. The influence of reactor design on the reaction of interest, comparing batch and continuous flow systems from lab to industrial scales, is discussed. Critical arguments about heterogeneous catalytic processes for CO2 conversion using nanostructured carbons are summarized. Despite the excellent catalytic performance, considerable work remains to be done to understand the commercial and large-scale applicability of these carbon-based materials. Therefore, underlying challenges, potential drawbacks, and an in-depth understanding of the mechanistic synergism between the active acidic and basic sites coupled and supported by computational studies have been provided which will further help to generate ideas for design, modification, and tailoring of a new generation of nanostructured carbon-based materials for potential use as catalytic systems for CO2 reactions and organic transformations.