Polyaniline-functionalized carbon nanotube supported platinum catalysts

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing stable and efficient electrocatalysts is crucial for advancing proton exchange membrane fuel cells (PEMFCs).
• Carbon nanotubes (CNTs) offer excellent conductivity and surface area, but uniform dispersion and strong interaction with metal nanoparticles can be challenging.
• Polyaniline (PANI) is a conductive polymer with potential for stabilizing nanoparticles and enhancing interfacial properties.

Purpose of the Study:

• To synthesize and characterize a novel electrocatalyst comprising platinum nanoparticles (Pt NPs) anchored on polyaniline-modified carbon nanotubes (PANI/CNT).
• To investigate the role of polyaniline in bridging Pt NPs and CNTs and enhancing catalyst stability and electroactivity.
• To evaluate the potential of the Pt-PANI/CNT catalyst for applications in proton exchange membrane fuel cells.

Main Methods:

• Platinum nanoparticle colloids were prepared via ethanol reduction, protected by aniline.
• Carbon nanotubes were dispersed using aniline, followed by polymerization of aniline in the presence of HCl and NH(4)S(2)O(8) to form PANI.
• The synthesized PANI wrapped around CNTs via π-π bonding, facilitating the loading of highly dispersed Pt NPs (2.0–4.0 nm) through Pt-N bonding and polymer stabilization.

Main Results:

• The synthesized PANI effectively wrapped around CNTs, forming π-π interactions.
• Highly dispersed platinum nanoparticles with narrow size distribution (2.0–4.0 nm) were successfully loaded onto the PANI/CNT support.
• Evidence of platinum-nitride (Pt-N) bonding and π-π bonding between PANI and CNTs was observed, contributing to catalyst stability.
• The resulting Pt-PANI/CNT catalysts demonstrated excellent electroactivity and electrochemical stability.

Conclusions:

• The integration of polyaniline as a bridging agent significantly enhances the nucleation and stability of platinum nanoparticles on carbon nanotubes.
• The synergistic effects of Pt-N and π-π bonding contribute to the superior performance of the Pt-PANI/CNT electrocatalyst.
• This novel catalyst exhibits promising potential for efficient and durable operation in proton exchange membrane fuel cells.