From Transient Fluctuations to Programmable Dynamics: Operando-Reversible Reconstruction of Single-Atom Sites

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Single-atom catalysts exhibit dynamic coordination fluctuations, offering mechanistic insights but posing challenges in control and exploitation.
• Current methods struggle to harness the dynamic nature of single-atom sites due to their elusive and uncontrollable behavior.

Purpose of the Study:

• To shift from stochastic fluctuations to programmable coordination switching in single-atom catalysts.
• To develop a model catalyst with operando-reversible reconstruction of single-atom copper (Cu) sites.
• To demonstrate adaptive responsiveness to redox and acid-base environments for enzyme-mimetic catalysis.

Main Methods:

• Utilized a Pt/bpy-UiO-CuX2 model catalyst system.
• Employed operando-reversible reconstruction of single-atom Cu sites triggered by reductive environments.
• Applied multimodal operando spectroscopy and theoretical calculations.

Main Results:

• Achieved programmable coordination switching of single-atom Cu sites between N2-Cu-H and Cu-(OH)2 configurations.
• Demonstrated reprogramming of coordination anions (Cl-, OH-, sulfate) via external environments.
• Showed that the N2-Cu-H intermediate enhances phenylacetylene-to-styrene selectivity by modulating the Pt active center's electronic state.

Conclusions:

• Established a new paradigm for dynamic single-atom catalysts, moving from stochastic fluctuations to programmable coordination switching.
• Developed a model catalyst with adaptive responsiveness to redox and acid-base conditions.
• The findings pave the way for designing advanced enzyme-mimetic catalysts with enhanced performance and control.