First-Principles Study on the Single Ir Atom Embedded Graphdiyne: An Efficient Catalyst for CO Oxidation

Abstract

Single-atom catalysts have attracted wide attention due to the maximum usage of single atom and the great potential to achieve high activity and selectivity. The oxidation of CO molecules on the single Ir atom embedded graphdiyne (Ir-GDY) has been investigated by using the first-principles calculations. A variety of reaction mechanisms are taken into account and a new pathway is found to catalyze CO oxidation more efficiently on Ir-GDY. A comparison of the reaction energy barrier shows that the CO oxidation likely occurs in the new Eley–Rideal (NER) mechanism rather than the traditional mechanism. In the NER mechanism, the adsorbed O2 molecule is activated by two physisorbed CO molecules thereby formed two CO2 synchronously with the energy barrier of 0.37 eV, as the rate-limiting step. In this reaction, the electrons are transferred from the substrate to the O2 and the CO, which promotes the decomposition of O2. After the C–C bond cleavage, the OOCCOO intermediate dissociates to form two CO2 molecules, in which the electrons return to the substrate and then start a new round of oxidation. We also found that the Langmuir–Hinshelwood (0.77 eV) and termolecular Eley–Rideal (0.70 eV) mechanisms are also likely to proceed. Therefore, the Ir-GDY is an efficient catalysis for CO oxidation.

Theoretical Calculation of Different Reaction Mechanisms for CO Oxidation on MnN3-Doped Graphene

“…Lu et al found that single Ir atom-embedded graphdiyne can catalyze CO oxidation more efficiently through the NER mechanism with the activation energy of 0.37 eV. 47 Keke Mao et al found that a h-BN monolayer fixed single gold atom catalyzed CO preferring the TER reaction with an energy barrier of 0.47 eV. 48 Next, we comprehensively analyze the four oxidation mechanisms.…”

Single‐Atom Catalysts in Catalytic Biomedicine

“…Furthermore, the current research focusing on biomedical applications of SACs mainly concentrates on cancer treatment, wound disinfection, biosensing, and oxidative‐stress cytoprotection, while other biomedical applications including diagnosis, multimodal imaging, inflammation alleviation as well as Alzheimer's disease, Parkinson's disease, and diabetes treatment are rarely studied. In addition, although numerous SACs have been successfully fabricated, including diverse single metal atoms (Au, Co, Fe, Ir, Ru, Pt, Pd, etc.) on various supports such as N‐doped carbon, metal oxides, and layered double hydroxides, only Fe‐, Au‐, Zn‐, and Cu‐based SACs, especially M‐N‐C nanostructures, have been demonstrated their potential in biomedical applications.…”

Single‐atom Automobile Exhaust Catalysts

“…DFT-based studies showed that Ir 1 /graphdiyne preferentially follows the TER mechanism in which O 2 bridges with two adsorbed CO molecules, forming two CO 2 molecules. [66] In summary, the catalytic performance and reaction mechanisms of Rh/Ir SACs are highly affected by their supports. MvK, ER, and TER mechanisms were reported on different supports.…”