Local Proton-Rich Solid Solution Catalyst with a Cluster-in-Cluster Structure for Anti-interference Seawater...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Poor proton coverage in electrocatalysts limits neutral hydrogen evolution reaction (HER) efficiency.
• Electrocatalysts struggle with alkali hydroxides in seawater, creating a gap with acidic water splitting.
• Direct seawater splitting requires catalysts with enhanced activity and stability in challenging conditions.

Purpose of the Study:

• To develop a novel catalyst for efficient and stable direct seawater splitting.
• To address the limitations of proton coverage and alkali hydroxide resistance in neutral HER.
• To investigate a cluster-in-cluster solid solution catalyst for improved electrocatalytic performance.

Main Methods:

• Synthesis of a cluster-in-cluster solid solution catalyst: amorphous hafnium oxide (HfO_x) in crystalline iridium (Ir).
• Characterization using techniques like in situ FT-IR and Raman spectroscopy.
• Theoretical calculations to understand the catalyst's mechanism and interfacial properties.

Main Results:

• The HfO_x-in-Ir solid solution catalyst (SSC) creates a proton-rich microenvironment.
• Achieved a low overpotential of 30 mV in neutral electrolytes due to optimized *H adsorption.
• Demonstrated superior anti-poisoning against Cl^-/ClO^- and anti-deposition of Mg(OH)₂, with an ultra-low overpotential of 117 mV at 10 mA cm^-2 in seawater.

Conclusions:

• The HfO_x-in-Ir SSC exhibits exceptional activity and stability for direct seawater splitting.
• The catalyst's design overcomes key challenges in neutral HER and harsh seawater environments.
• This work offers a promising pathway for efficient hydrogen production from seawater.