Tackling CO Poisoning with Single-Atom Alloy Catalysts

Area of Science:

• Materials Science
• Catalysis
• Surface Chemistry

Background:

• Platinum (Pt) catalysts are vital in industry and fuel cells but are deactivated by carbon monoxide (CO) adsorption.
• Strong CO binding to Pt surfaces is a major limitation for catalyst stability and longevity.

Purpose of the Study:

• To develop a platinum-based catalyst with reduced CO binding strength while preserving catalytic activity.
• To investigate the single-atom alloy (SAA) strategy for enhancing CO tolerance in platinum catalysts.

Main Methods:

• Utilized surface-sensitive studies to quantify CO binding strengths on different platinum ensembles.
• Prepared platinum-copper (PtCu) alloy nanoparticles (NPs) with controlled compositions.
• Employed acetylene hydrogenation as a probe reaction to assess catalyst performance under CO exposure.

Main Results:

• A PtCu SAA with a Pt:Cu ratio of 1:125 demonstrated significantly reduced CO binding.
• The SAA catalyst exhibited excellent CO tolerance during H2 activation, essential for hydrogenation and electro-oxidation.
• Selective hydrogenation of acetylene to ethene proceeded without activity loss in the presence of CO on the SAA NPs.

Conclusions:

• The SAA strategy effectively mitigates CO poisoning in platinum catalysts by weakening CO adsorption.
• PtCu SAA catalysts offer a promising solution for applications requiring high CO tolerance, including fuel cells and industrial hydrogenation.
• This approach has broad implications for enhancing catalyst stability in various chemical processes sensitive to CO inhibition.