Bifunctional single-atomic Mn sites for energy-efficient hydrogen production

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Electrocatalytic hydrogen evolution reaction (HER) is key for H2 production.
• Efficiently screening catalysts is challenging due to sluggish oxygen evolution reaction (OER) kinetics.
• Alternative pathways are needed for energy-saving H2 generation.

Purpose of the Study:

• To develop a highly active and low-cost catalyst for efficient hydrogen production.
• To investigate a hydrazine electrooxidation reaction (HzOR) boosted water electrolysis system.
• To demonstrate a novel single-atomic catalyst for clean energy applications.

Main Methods:

• Synthesized a single atomic Mn site anchored on a boron-nitrogen co-doped carbon nanotube array (Mn-SA/BNC).
• Evaluated the catalyst's performance in cathodic HER and HzOR.
• Tested the catalyst in a two-electrode overall hydrazine splitting (OHzS) system.

Main Results:

• Achieved 51 mV overpotential for HER at -10 mA cm-2.
• Required 132 mV vs. RHE for HzOR.
• Demonstrated a low cell voltage of 0.41 V for 10 mA cm-1 in the OHzS system with high durability and nearly 100% faradaic efficiency for H2 production.

Conclusions:

• The Mn-SA/BNC catalyst offers a highly efficient and energy-saving pathway for H2 production.
• Single-atomic catalysts combined with hydrazine electrooxidation present a promising strategy for renewable energy.
• This approach addresses the challenge of sluggish OER kinetics in water electrolysis.