Embedding Single Pd Atoms on NiGa Intermetallic Surfaces for Efficient and Selective Alkyne Hydrogenation

Area of Science:

• Heterogeneous catalysis
• Materials science
• Surface chemistry

Background:

• Alkyne removal is crucial for producing polymer-grade alkenes.
• Non-noble Ni-based catalysts are promising but have low activity.
• Industrial processes often use Pd-based catalysts.

Purpose of the Study:

• To design a highly active and selective catalyst for alkyne semi-hydrogenation.
• To improve the performance of Ni-based catalysts using single-atom doping.
• To explore synergistic effects between single-atom Pd and NiGa intermetallic surfaces.

Main Methods:

• Synthesis of single-atom palladium embedded NiGa intermetallic (Pd1-NiGa).
• Characterization of the catalyst structure and composition.
• Experimental evaluation of catalytic activity and selectivity for alkyne semi-hydrogenation.
• Computational studies (e.g., DFT) to understand reaction mechanisms.

Main Results:

• The Pd1-NiGa catalyst, specifically Pd1Ni2Ga1 ensemble sites, demonstrated significantly higher specific mass activity.
• Achieved excellent alkene selectivity (>96%) under industry-relevant conditions.
• Identified synergistic effects between single-atom Pd and Ni sites enhancing alkyne adsorption and H2 dissociation.
• Demonstrated suppression of alkene adsorption, preventing over-hydrogenation.

Conclusions:

• Single-atom Pd on NiGa intermetallic surfaces is a highly effective strategy for alkyne semi-hydrogenation.
• The developed catalyst outperforms state-of-the-art catalysts in activity and selectivity.
• This approach offers a pathway to enhance low-activity Ni-based catalysts for various selective hydrogenation applications in industry.