Rationalization of promoted reverse water gas shift reaction by Pt₃Ni alloy: Essential contribution from ensemble...

Area of Science:

• Materials Science
• Catalysis
• Computational Chemistry

Background:

• Bimetallic alloys offer tunable catalytic properties distinct from pure metals.
• Understanding alloy behavior is crucial for developing efficient catalysts.
• The reverse Water Gas Shift (rWGS) reaction is important for CO2 utilization.

Purpose of the Study:

• To investigate the superior catalytic performance of Pt3Ni nanowires (NWs) compared to pure Pt and Ni NWs.
• To elucidate the underlying mechanisms, particularly the role of ensemble effects, in the rWGS reaction.
• To explore the synergistic interactions between Pt and Ni in the bimetallic alloy.

Main Methods:

• Density functional theory (DFT) calculations were employed to study the catalytic behaviors.
• Analysis focused on the Pt3Ni NW surface, including specific edge sites.
• Comparison was made with individual Pt and Ni NWs.

Main Results:

• Pt3Ni NWs exhibited significantly enhanced activity for the rWGS reaction.
• The ensemble effect, arising from the specific arrangement of Pt and Ni sites, was identified as the primary driver of activity.
• A unique Ni-Pt hybrid ensemble at the 110/111 edge facilitated CO2 stabilization and CO/H2O formation.

Conclusions:

• The ensemble effect in bimetallic alloys plays a critical role in tuning catalytic activity and selectivity.
• Pt3Ni NWs demonstrate a promising catalytic system for the rWGS reaction due to synergistic Ni-Pt interactions.
• This study underscores the importance of considering ensemble effects for designing advanced heterogeneous catalysts.