β-Functionalized Push-Pull Monobenzoporphyrins: Synthesis, Photophysical, Structural Properties, and Electrocatalytic...

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Hydrogen production via water splitting is crucial for sustainable energy.
• Efficient and cost-effective catalysts are needed for the hydrogen evolution reaction (HER).
• Porphyrin derivatives offer tunable electronic and structural properties for catalysis.

Purpose of the Study:

• To synthesize and evaluate electronically tunable β-functionalized push-pull monobenzoporphyrins.
• To investigate the electrocatalytic activity of their cobalt(II) derivatives for HER.
• To provide structural insights into catalyst performance for improved hydrogen evolution technologies.

Main Methods:

• Synthesis and characterization of push-pull monobenzoporphyrins (NMR, MS, UV-vis).
• Single-crystal X-ray analysis and DFT calculations for structural determination.
• Electrocatalytic evaluation of cobalt(II) complexes for HER in H2SO4 (potentiostatic methods, EIS, chronoamperometry).

Main Results:

• Successful synthesis of MTPP(Benzo)(R)2 (R = CH3, Ph, tBu-Ph, Py; M = 2H, Co(II)).
• CoTPP(Benzo)(CH3)2 exhibited a saddle-shaped conformation.
• Cobalt(II) catalysts showed significantly reduced overpotentials (254-487 mV) and lower Tafel slopes (238-298 mV dec-1) compared to CoTPP.
• Enhanced catalytic efficiency, kinetics, and stability were observed for the push-pull porphyrin catalysts.

Conclusions:

• Electronically tunable push-pull CoTPP(Benzo)(R)2 complexes are effective electrocatalysts for HER.
• Structural modifications significantly improve catalytic performance, reducing overpotentials and enhancing kinetics.
• These porphyrin-based catalysts offer a sustainable and efficient alternative for hydrogen production.