Surface Protonics Promotes Catalysis.

Area of Science:

• Catalysis
• Surface Science
• Hydrogen Production

Background:

• Methane steam reforming is a key process for hydrogen production.
• Low-temperature catalysis often faces kinetic limitations.
• Electric fields can potentially influence catalytic reactions.

Purpose of the Study:

• To investigate the promotion of catalytic steam reforming of methane by surface protonics in an electric field.
• To elucidate the mechanism of methane activation at low temperatures under electric field application.

Main Methods:

• Catalytic steam reforming experiments using 1 wt% Pd/CeO2 catalyst at 473 K.
• Kinetic analysis to determine reaction rate dependencies and activation energy.
• Operando-Infrared (IR) spectroscopy to study surface species and proton conduction.
• Kinetic isotope effect studies to probe reaction mechanisms.

Main Results:

• Catalytic steam reforming of methane proceeded efficiently at 473 K in an electric field.
• A synergetic effect between the electric field and the catalyst was observed, reducing apparent activation energy.
• Operando-IR confirmed proton conduction via adsorbed water on the catalyst surface under an electric field.
• Methane activation was attributed to proton collision at the Pd-CeO2 interface, supported by an inverse kinetic isotope effect.

Conclusions:

• Surface protonics, facilitated by an electric field, significantly promote methane steam reforming at low temperatures.
• Proton conduction on the catalyst surface is crucial for low-temperature methane activation.
• This study presents the first evidence of catalytic reaction promotion by surface protonics.