Density functional theory calculations on the CO catalytic oxidation on Al-embedded graphene

Abstract

The oxidation of CO molecules on Al-embedded graphene has been investigated by using the first principles calculations. Both Eley-Rideal (ER) and Langmuir-Hinshelwood (LH) oxidation mechanisms are considered. In the ER mechanism, an O 2 molecule is first adsorbed and activated on Al-embedded graphene before a CO molecule approaches, the energy barrier for the primary step (CO + O 2 / OOCO) is 0.79 eV. In the LH mechanism, O 2 and CO molecules are firstly co-adsorbed on Al-embedded graphene, the energy barrier for the rate limiting step (CO + O 2 / OOCO) is only 0.32 eV, much lower than that of ER mechanism, which indicates that LH mechanism is more favourable for CO oxidation on Al-embedded graphene. Hirshfeld charge analysis shows that the embedded Al atom would modify the charge distributions of co-adsorbed O 2 and CO molecules. The charge transfer from O 2 to CO molecule through the embedded Al atom plays an important role for the CO oxidation along the LH mechanism.Our result shows that the low cost Al-embedded graphene is an efficient catalyst for CO oxidation at room temperature.

A promising single atom catalyst for CO oxidation: Ag on boron vacancies of h-BN sheets

“…32,61 Moreover, a previous study has shown that the HOMO of the CO molecule (5s) has weight mainly around the C atom, 62 indicating that CO always acts as a donor when its C end points to the anchoring atom. The current phenomenon is similar to the positively charged CO over Al/graphene, 28 Pd/BN 56 and Pt/BNNT. 63 Both the 5s and 1p orbitals of CO hybridize with the Ag-4d states in the energy range from À8 eV to À6 eV, and the two Ag-4d peaks near the Fermi level also overlap with the 2p* orbitals of CO, confirming the strong interaction between Ag and CO.…”

“…To this end, experimental research has shown that oxide supports such as MgO, 20 FeO x , 19 SiO 2 22 and TiO 2 23 or graphitic layers 24 can anchor single metal atoms and hence allow synthesis of SACs by using the mass-selected soft-landing technique, improved wet chemistry methods, or atomic layer deposition methods. 19,20,24 Particularly, two-dimensional (2D) materials with a large surface area and high thermal stability, such as graphene, [25][26][27][28][29] graphyne, 30,31 MoS 2 32 and freestanding hexagonal boron nitride monolayers (h-BN), 33,34 can be used as prominent supports to host single metal atoms, which exhibit superb catalytic activity for CO oxidation. [35][36][37][38] Recent experimental studies also showed that Ag supported by BN nanosheets with good thermal stability can be used as an effective catalyst for the reduction of p-nitrophenol 39,40 and the methanol oxidation reaction.…”

A DFT study on SO3 capture and activation over Si- or Al-doped graphene

“…As it is clear, the average bond length of Si (Al) atom with its neighboring C atoms is 1.73 (1.84) Å which is about 0.31 (0.42) Å larger than the average C-C bond length in the pristine graphene. This value is in good agreement with other related estimates for the Si-and Al-doped graphene [36][37][38]. In both cases, the dopant atom a little protrudes out of the graphene surface to get more space due to its relatively larger atomic radius than that of C atom.…”

A Comparative Study of CO Oxidation on Nitrogen‐ and Phosphorus‐Doped Graphene

“…Thisc alculated E ads value is smaller than the corresponding one (1.18) on Al- [26] and Si-embedded graphene. [45] Although as imilar adsorption pattern is achievedw ith the PBEPBE method, but the calculated binding distance is relatively larger and the adsorption energy is less negative.…”

“…[23,24] For instance, Lu et al [25] reported that Au-doped graphene exhibits ah igh catalytic activity toward CO oxidation. Jiang et al, [26] in another theoretical study,f ound that the low energy barrier (7.4 …”