Microwave effects on NiMoS and CoMoS single-sheet catalysts.

Area of Science:

• Catalysis
• Materials Science
• Physical Chemistry

Background:

• Single-sheet nanoclusters of MoS2, NiMoS, and CoMoS are crucial for hydrodesulfurization (HDS) in petroleum refining.
• Microwave irradiation is known to accelerate HDS reactions, with hot spots suggested as the underlying mechanism for pristine MoS2.

Purpose of the Study:

• To investigate and quantify the effect of microwave irradiation on NiMoS and CoMoS catalysts compared to MoS2.
• To elucidate the atomic origin of microwave-induced hot spots in these catalytic systems.

Main Methods:

• Utilized density functional theory (DFT) to analyze molecular charge densities.
• Employed Stone's distributed multipole analysis (DMA) for charge decomposition.
• Correlated site dipole values with microwave field interactions.

Main Results:

• Microwave enhancement of HDS reaction rates follows the order: CoMoS > NiMoS > MoS2.
• Established a clear link between catalyst composition and microwave interaction efficiency.
• Identified the atomic origin of microwave-induced hot spots in promoted CoMoS and NiMoS clusters.

Conclusions:

• CoMoS and NiMoS catalysts exhibit superior microwave-driven HDS enhancement compared to MoS2.
• The study provides a fundamental understanding of microwave-catalyst interactions at the atomic level.
• This work offers insights for designing more efficient catalysts for HDS under microwave irradiation.