Constructing Atomic Tungsten-Based Solid Frustrated-Lewis-Pair Sites with d-p Interactions for Selective CO₂...

Area of Science:

• Materials Science
• Catalysis
• Photochemistry

Background:

• Solid frustrated Lewis pairs (FLPs) effectively activate small molecules like CO2 via orbital interactions.
• Current FLP catalysts suffer from low site utilization due to random distribution and aggregation.
• Efficient CO2 activation is crucial for sustainable chemical synthesis and environmental remediation.

Purpose of the Study:

• To construct and investigate atomic tungsten-based FLP (N···W_SA FLP) sites for enhanced photocatalytic CO2 conversion.
• To understand the mechanism of CO2 activation and reduction facilitated by these atomically dispersed FLP sites.
• To provide a new strategy for designing highly efficient single-atom-based FLP catalysts.

Main Methods:

• Synthesis of atomic tungsten-based FLP sites by introducing W single-atoms into polymeric carbon nitride.
• Characterization using pyridine-IR, in situ DRIFTS, and CO2-TPD.
• Theoretical calculations to elucidate the electronic structure and reaction mechanism.
• Photocatalytic CO2 reduction experiments.

Main Results:

• Atomically dispersed N···W_SA FLP sites were successfully constructed, with W single-atoms acting as Lewis acids and adjacent N atoms as Lewis bases.
• The N···W_SA FLP effectively adsorbs CO2, forming a unique W-O-C-N structure with significant d-p orbital interactions.
• A novel
• push-push
• electron transfer mechanism was identified, involving π back-donation and Lewis acid-base interactions, leading to efficient C═O bond breaking.
• Enhanced CO2-to-CO conversion performance was achieved.

Conclusions:

• Atomic tungsten-based FLP sites offer a highly effective strategy for activating CO2.
• The unique electronic structure and interaction within the N···W_SA FLP facilitate efficient photocatalytic CO2 reduction.
• This work presents a promising new avenue for developing single-atom FLP catalysts for small molecule activation.