Bond-making and breaking between carbon, nitrogen, and oxygen in electrocatalysis

Area of Science:

• Heterogeneous catalysis
• Surface science
• Computational chemistry

Background:

• Catalytic reactions involving small molecules are vital for sustainable energy and chemistry, often involving carbon, nitrogen, and oxygen bonds.
• Many heterogeneously catalyzed reactions show unusual structure sensitivity, favoring specific two-dimensional (100) surface structures.
• Steps and defects on these surfaces typically reduce catalytic activity, suggesting the presence of a special active site.

Purpose of the Study:

• To identify the specific active site responsible for the structure sensitivity in heterogeneously catalyzed reactions.
• To provide an atomic-level explanation for the reduced reactivity at steps and defects on catalyst surfaces.
• To offer new design principles for developing efficient catalysts for crucial bond-making and bond-breaking reactions.

Main Methods:

• Utilizing detailed density functional theory (DFT) calculations.
• Investigating a variety of catalytic reactions involving small molecules.
• Analyzing the electronic structure and bonding at different surface sites.

Main Results:

• Identified a unique active site on two-dimensional (100) terraces that drives catalytic activity.
• Demonstrated how this specific site breaks the conventional rule of stronger binding at under-coordinated sites.
• Showed significant deviations from established energetic scaling relations due to this unique binding behavior.

Conclusions:

• The identified active site provides an atomic-level understanding of structure sensitivity in these reactions.
• The findings explain the lower reactivity of steps and defects, challenging common assumptions.
• This research offers new guidelines for designing thermodynamically efficient catalysts for key chemical transformations.