WS₂ supported PtO clusters for efficient photocatalytic CO₂ reduction: a DFT study.

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Platinum (Pt) nanoparticles are effective cocatalysts for photocatalytic CO₂ reduction.
• Strong CO adsorption on Pt can cause catalyst poisoning.
• Developing stable and efficient cocatalysts is crucial for CO₂ conversion.

Purpose of the Study:

• To investigate the use of platinum oxide (PtO) clusters of varying sizes loaded on WS₂ as cocatalysts for photocatalytic CO₂ reduction.
• To understand the role of PtO clusters in enhancing CO₂ conversion efficiency and mitigating CO poisoning.
• To explore the relationship between catalyst structure, adsorption properties, and photocatalytic activity.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• The stability and electronic properties of PtO-WS₂ (with Pt₄O₆, Pt₅O₈, Pt₇O₁₀, and Pt₈O₁₃ clusters) were evaluated.
• The free energy changes (ΔG) for key reaction steps in CO₂ reduction were calculated.
• Adsorption strengths of intermediates on the catalysts were analyzed.

Main Results:

• PtO-WS₂ catalysts exhibit high stability and beneficial electron-rich PtO clusters.
• All PtO-WS₂ catalysts demonstrated efficient photocatalytic CO₂ reduction.
• Specific catalysts (Pt₄O₆-, Pt₅O₈-, and Pt₈O₁₃-WS₂) showed ultra-low ΔG_max for producing methanol, formic acid, and methane.
• Catalyst activity correlates with intermediate adsorption strength, particularly *COOH and *HCOO.
• PtO-WS₂ effectively weakens *CO and *HCOOH adsorption, facilitating *CHO formation.

Conclusions:

• PtO-WS₂ systems are promising for efficient photocatalytic CO₂ reduction.
• The electronic properties and tunable adsorption of PtO clusters are key to high catalytic activity.
• This study provides insights for designing advanced catalysts to improve CO₂ conversion efficiency and selectivity.