Catalytic activity of silicene biflakes for CO₂ reduction: a theoretical approach

Abstract

The use of renewable energy sources to reduce carbon dioxide (CO2) emissions has gained significant attention in recent years. The catalytic reduction of CO2 into value-added products is a promising...

Enhancing CO2 reduction through the catalytic effect of a novel silicon haeckelite-inspired 2D material

“…48 For this reason, a “cluster” approach is used to calculate the broken symmetry wave function of the minima and the transition states, which is not possible with the PBC method. Likewise, the reaction mechanism of CO 2 reduction on silicene monoflakes 46 and biflakes 47 has been reported at the same level of theory used in this study for comparative purposes.…”

“…Similar geometrical changes have been detected in CO 2 chemisorption on silicene surfaces. 45,47 Furthermore, the adduct Hck-CO 2 ( 55 ) (Fig. 4 and 5(A), (B)) exhibits a negative relative energy compare to the isolated CO 2 and Hck .…”

“…The same occurs with the monolayered silicene, 46 which is not completely planar, but the bilayered structure is. 47 To compare the results obtained by the three DFT functionals and the periodic system, some structural parameters were chosen, namely, the Si–Si distances, d1–d4 , and angles, α1–α3 , respectively, as shown in Table 1.…”

“…In contrast, the same adduct generated by silicene mono- and biflakes shows positive energies of 15.5 and 13.3 kcal mol −1 , respectively. 46,47 This means that Hck could capture CO 2 spontaneously, while the honeycomb silicene structures require energy to form adducts with carbon dioxide molecules.…”

“…Recently, we reported two studies on CO 2 reduction in silicene monolayers 46 and bilayers. 47 The results showed that the reaction pathway involved the adsorption of CO 2 on the silicene surface, followed by the addition of hydrogen molecules to form products such as formic acid, formaldehyde, carbon monoxide, methanol, and methane. Our proposed mechanism indicates that the silicene bilayer exhibits a higher affinity for CO 2 than the monolayered silicene.…”