Homonuclear/Heteronuclear Bimetallic Conjugated Coordination Polymers with Customized Oxygen Evolution Pathway.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Synergistic effects in bimetallic catalysts for oxygen evolution reaction (OER) are not fully understood due to complex structures.
• Synthesizing catalysts with long-range atomic ordering for OER remains challenging.

Purpose of the Study:

• To investigate structure-property correlations in bimetallic catalysts for OER.
• To develop novel two-dimensional (2D) conjugated bimetallic coordination polymers (c-CPs) with well-defined structures.

Main Methods:

• Synthesis of two-dimensional (2D) conjugated bimetallic coordination polymers (c-CPs) involving Cobalt (Co) and Nickel (Ni).
• Electrocatalytic testing of synthesized catalysts for the oxygen evolution reaction (OER).
• Analysis of catalytic mechanisms using electrochemical techniques.

Main Results:

• The heteronuclear CoNi-PI catalyst unexpectedly shifted OER mechanisms from adsorbate evolution to the faster oxide path mechanism.
• CoNi-PI demonstrated high stability and an ultralow overpotential of 282 mV at 100 mA cm^-2.
• A low Tafel slope of approximately 42 mV dec^-1 was observed for CoNi-PI, indicating efficient kinetics.

Conclusions:

• This study presents a rare crystalline heteronuclear bimetallic catalyst with exceptional OER catalytic properties.
• The findings offer significant insights into catalyst development for efficient OER.
• Understanding the altered catalytic mechanism in CoNi-PI provides a foundation for designing advanced catalysts.