Haeckelite mediated reduction of CO2 by molecular hydrogen. A DFT study

[Display omitted] •Haeckelite is capable of accelerating CO2 reduction by 7 to 29 orders of magnitude.•Haeckelite favors the formation of formic acid over carbon monoxide upon the first addition of a hydrogen molecule.•The source of haeckelite's catalytic effect lies in the weakening of the HH bond in a hydrogen molecule due to its interaction with the haeckelite surface.•Haeckelite's catalytic activity is related to reduced aromatic stabilization compared to graphene. In this study, we conducted a theoretical exploration of haeckelite-mediated CO2 reduction with molecular hydrogen. We used a haeckelite nanoflake (NF) consisting of 96 carbon atoms passivated with hydrogens to elucidate the reaction mechanism on the 2D surface. The most favorable reaction pathway involves the sequential formation of formic acid, formaldehyde, methanol, and ultimately methane. Notably, formic acid formation is favored over carbon monoxide. Haeckelite-mediated reactions exhibit Gibbs-free activation energies 10 to 40 kcal/mol lower compared to processes without a catalyst. This catalytic effect is attributed to the interaction of H2 with the haeckelite surface, which weakens or breaks the HH bond. This theoretical perspective provides significant insights into carbon-based materials and their potential applications in transforming CO2 into fuels and value-added chemicals.