Thermal Migration to Recover Spent Pt/C Catalyst.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Spent platinum on carbon (Pt/C) catalysts hinder the widespread adoption of hydrogen fuel cells.
• Developing cost-effective and sustainable catalyst recovery methods is crucial for advancing fuel cell technology.

Purpose of the Study:

• To introduce a novel thermal migration strategy for recovering spent Pt/C catalysts.
• To create a new nitrogen-doped porous carbon (NC) support with pyrimidine nitrogen sites for enhanced platinum anchoring.

Main Methods:

• Synthesized nitrogen-doped porous carbon (NC) from ZIF-8.
• Employed a thermal migration process involving spent Pt/C, NC, and ammonium chloride (NH4Cl) at 900°C.
• Utilized NH4Cl as an etching reagent to facilitate platinum migration and anchoring onto NC.

Main Results:

• Successfully recovered platinum onto the NC support, forming Pt clusters and 4-5 nm Pt particles.
• The recovered Pt/NC catalyst demonstrated excellent oxygen reduction reaction (ORR) activity.
• Achieved a high mass activity of 0.6 A mgPt⁻¹ after an accelerated durability test of 30,000 cycles.

Conclusions:

• The thermal migration strategy is an effective and sustainable method for recovering spent Pt/C catalysts.
• The pyrimidine nitrogen sites in the NC support play a key role in anchoring platinum nanoparticles.
• The recovered Pt/NC catalyst exhibits superior stability and activity, making it promising for large-scale hydrogen fuel cell applications.