Ethane Dehydrogenation over the Core-Shell Pt-Based Alloy Catalysts: Driven by Engineering the Shell Composition and...

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Platinum (Pt)-based catalysts are crucial for industrial ethane dehydrogenation (EDH).
• A major challenge is balancing coke formation with catalytic activity.
• Core-shell Pt@Pt3Sn and Pt3Sn@Pt catalysts offer a potential strategy for performance enhancement.

Purpose of the Study:

• To theoretically investigate the catalytic performance of core-shell Pt-Sn catalysts for EDH.
• To explore the impact of shell surface structure and thickness on catalyst activity and selectivity.
• To identify optimal catalyst designs for improved EDH performance.

Main Methods:

• Density Functional Theory (DFT) calculations to model the EDH reaction network, including side reactions.
• Kinetic Monte Carlo (kMC) simulations to assess catalyst behavior under varying conditions (temperature, pressure).
• Comparison of eight core-shell catalyst designs with industrial Pt and Pt3Sn catalysts.

Main Results:

• CHCH* was identified as the primary precursor for coke formation.
• Pt@Pt3Sn catalysts generally exhibited higher C2H4(g) activity but lower selectivity than Pt3Sn@Pt catalysts.
• The 1Pt3Sn@4Pt catalyst demonstrated significantly higher C2H4(g) activity and 100% selectivity, surpassing other designs and commercial catalysts.

Conclusions:

• Rational engineering of core-shell catalyst shell structure and thickness is vital for optimizing EDH performance.
• The 1Pt3Sn@4Pt catalyst is a promising candidate for highly selective and active ethane dehydrogenation.
• Proposed descriptors (C2H5* adsorption energy and its dehydrogenation energy) can predict catalyst selectivity and activity.