Amorphous MoO_x Interfaces Activate Pt Nanoclusters for Ultralow-Overpotential Chlorine Evolution.

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Direct seawater electrolysis is a promising route for co-producing hydrogen and chlorine.
• Challenges include sluggish halide activation and platinum (Pt) dissolution at low chloride concentrations.

Purpose of the Study:

• To develop a catalyst that enhances chlorine evolution efficiency and stability in seawater.
• To investigate the mechanism of catalyst performance improvement.

Main Methods:

• In situ amorphization of molybdenum oxide to create a dynamic metal-support interface.
• Utilizing platinum (Pt) nanoclusters on the engineered interface.
• Employing operando Raman spectroscopy to study reaction mechanisms.

Main Results:

• The amorphous-interface catalyst achieved nearly 100% chlorine selectivity and a low overpotential (65 mV at 10 mA cm⁻²).
• Achieved a mass activity 26-fold higher than conventional Pt/C catalysts.
• Demonstrated strengthened chloride adsorption and stabilized Pt against dissolution.

Conclusions:

• Amorphization-induced electronic interface engineering is a powerful strategy for electrocatalytic halogen evolution.
• The engineered interface facilitates halide activation and promotes efficient chlorine evolution via a Volmer-Tafel mechanism.
• This approach offers a pathway to stable and highly active catalysts for seawater electrolysis.