New way to study surfaces brings ‘real world’ pressure into the lab, PgII

Key Highlights:

• Researchers have developed a modified X-ray photoelectron spectroscopy (XPS) machine that can operate at atmospheric pressure.
• The innovation uses a de Laval nozzle to create a localized high-pressure zone on the sample surface.
• The system allows for the study of surface chemistry under realistic, non-vacuum conditions.
• The technology could enable scientists to study catalysts and corrosion in real-time in standard laboratories.

Detailed Insights:

• XPS is a crucial tool for analyzing material surfaces at the atomic level, but traditionally requires a vacuum environment.
• Real-world chemical reactions typically occur under atmospheric pressure, creating a "pressure gap" for conventional XPS.
• The modified XPS machine uses a de Laval nozzle to focus a jet of gas at supersonic speeds onto the sample surface, creating a localized pressure zone of up to 1 atm.
• This localized pressure allows for the study of surface chemistry at realistic pressures while maintaining a vacuum in the rest of the machine to protect the detectors.
• The team verified the pressure at the sample surface using computer simulations and a custom pressure sensor.
• The technology could lead to a better understanding of catalysts, corrosion, and other surface phenomena, potentially improving industrial processes.

Scientific/Technical Concepts Involved:

• X-ray Photoelectron Spectroscopy (XPS): A surface-sensitive technique that uses X-rays to analyze the elemental composition and chemical states of a material.
• De Laval Nozzle: A converging-diverging nozzle that accelerates gas to supersonic speeds, used here to create a localized high-pressure zone.
• Atmospheric Pressure: The pressure exerted by the Earth's atmosphere, approximately 1 atm or 101.325 kPa.