Unwrap Them First: Operando Potential- induced Activation Is Required when Using PVP-Capped Ag Nanocubes as Catalysts...

Area of Science:

• Nanomaterials Science
• Electrocatalysis
• Surface Chemistry

Background:

• Metallic nanoparticles are crucial electrocatalysts for CO₂ reduction.
• Organic capping agents (surfactants) are used in nanoparticle synthesis but can hinder catalytic activity.
• Conventional methods for removing capping agents include UV-ozone or plasma treatments.

Purpose of the Study:

• To demonstrate an electrochemical, operando activation method for poly-vinylpyrrolidone (PVP) capped silver nanocubes.
• To show that this method can eliminate the need for pre-catalyst cleaning steps.
• To investigate the hysteresis of catalytic yield as a function of applied potential.

Main Methods:

• Synthesis of poly-vinylpyrrolidone (PVP) capped silver nanocubes.
• Electrochemical characterization and CO₂ electroreduction experiments.
• Operando activation via potential excursion to remove blocking agents.

Main Results:

• As-synthesized nanocubes showed low CO yield at moderate overpotentials.
• Electrochemical activation at more negative potentials irreversibly removed blocking PVP.
• This activation significantly increased CO yield and catalyst efficiency under milder conditions.
• The activated catalyst demonstrated stable performance over extended operation.

Conclusions:

• An effective electrochemical, operando activation method for nanoparticle electrocatalysts was demonstrated.
• This method bypasses the need for ex situ cleaning of capping agents.
• The activation process leads to enhanced and stable catalytic performance for CO₂ electroreduction.