Monometallic dual-atom two-dimensional phthalocyanine-based metal-organic framework for carbon dioxide...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient catalysts are crucial for advancing electrochemical carbon dioxide reduction reaction (CO2RR) technology.
• Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) offer tunable structures for catalytic applications.

Purpose of the Study:

• To design and evaluate 14 types of 2D c-MOFs (PcM-O8-M) with monometallic dual-atom centers for CO2RR.
• To systematically investigate their catalytic performance, stability, and conductivity using density functional theory (DFT).

Main Methods:

• Density functional theory (DFT) calculations were employed to study 14 PcM-O8-M structures.
• Analysis of free energy diagrams to understand the CO2RR mechanism at MN4 and MO4 active sites.
• Machine learning was used to identify key descriptors for catalytic activity.

Main Results:

• All 14 PcM-O8-M exhibited robust thermodynamic and electrochemical stability with good conductivity.
• Four PcM-O8-M (M = Cr, Mo, Ru, Rh) showed high activity and selectivity for C1 products, with limiting potentials (UL) from -0.47 V to 0 V.
• A strong volcano relationship between ΔG*COOH and UL was observed, and atomic charge was identified as a key descriptor.

Conclusions:

• The study identified highly efficient PcM-O8-M electrocatalysts for CO2RR, particularly for C1 product generation.
• An intrinsic descriptor φ was identified, correlating well with catalytic activity (UL).
• These findings provide valuable insights for designing next-generation CO2RR electrocatalysts.