Hydrogen oxidation-driven hot electron flow detected by catalytic nanodiodes.

Area of Science:

• Surface chemistry
• Catalysis
• Materials science

Background:

• Platinum-catalyzed reactions are crucial in many chemical processes.
• Understanding electron dynamics in catalytic reactions is key to improving efficiency.

Purpose of the Study:

• To investigate the generation and detection of hot electrons during hydrogen oxidation on platinum.
• To establish a correlation between catalytic activity and electron transport.

Main Methods:

• Utilizing platinum/titanium dioxide (Pt/TiO2) Schottky diodes to detect electron flux.
• Performing kinetic studies under varying hydrogen and oxygen partial pressures and temperatures.

Main Results:

• Demonstrated that hydrogen oxidation on platinum produces a steady-state flux of hot conduction electrons (>1 eV).
• Observed a steady-state chemicurrent across Pt/TiO2 Schottky diodes exposed to hydrogen and oxygen.
• Found the chemicurrent to be proportional to the turnover frequency (298–373 K, 1–8 Torr H2, 760 Torr O2).
• Established a first-order dependence of both chemicurrent and turnover frequency on hydrogen partial pressure.

Conclusions:

• The chemicurrent is a direct measure of the catalytic turnover frequency for hydrogen oxidation on platinum.
• Hot electron generation is an intrinsic property of this surface catalytic reaction.