Mechanism of ethanol steam reforming on B12N12 and Al12N12 nano-cages: A theoretical study

Abstract

Density function theory calculations were employed in this study to investigate the ethanol steam reforming mechanism on B12N12 and Al12N12 nano-cages. The ethanol steam reforming on B12N12 and Al12N12 nano-cages was explored by OH, CαH, CαH, and CC bonds scission and forming hydrogen. The catalytic activity of two nano-cages was also assessed to identify a suitable catalyst. The calculations showed that ethanol steam consists of two stages of ethanol oxidation and water-gas shift reaction to produce H2 and CO2. Moreover, OH bond scission was a key step in ethanol steam reforming, and the formation of CH4 and CO in ethanol oxidation was favored. According to the calculations, the Al12N12 nano-cage was a more suitable catalyst due to its lower energy barrier in ethanol oxidation and water-gas shift reactions. Hirshfield charge analysis showed that with increasing metal property, more charge is transferred from the surface of Al12N12 nano-cage to intermediate species. The results clearly showed the mechanism and understanding of the importance of hydroxyl groups in ethanol vapor modification in B12N12 and Al12N12 nanocages, which could be useful in catalyst design and H2 formation.