Operando Study of the Active Phase in Liquid GaPt Alloy Catalysts

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Propane dehydrogenation (PDH) is crucial for producing propylene.
• Supported catalytically active liquid metal solutions (SCALMS) offer a novel catalytic approach.
• Understanding catalyst active phases during reactions is essential for optimization.

Purpose of the Study:

• To investigate the catalytic performance of a liquid gallium-platinum (GaPt) SCALMS for PDH.
• To monitor and analyze the catalyst's active phase and surface changes during the reaction.
• To demonstrate a method for achieving stable catalytic activity from the start.

Main Methods:

• Utilized *operando* near-ambient pressure X-ray photoelectron spectroscopy (NAPXPS).
• Combined NAPXPS with gas phase analysis for real-time monitoring.
• Employed a GaPt SCALMS with 1 at.% Pt content for PDH reactions.

Main Results:

• Metallic liquid GaPt SCALMS demonstrated high activity in PDH.
• Oxygen in the feed stream significantly decreased catalyst activity.
• Achieved stable conversion rates immediately, bypassing the typical activation period.
• Identified the critical influence of oxidic Ga on catalytic performance.

Conclusions:

• NAPXPS is a practical tool for real-time analysis of catalytic surfaces.
• The GaPt SCALMS catalyst shows promise for next-generation PDH catalysts.
• Optimizing Ga oxidation states is key for enhancing catalyst design and performance.