Platinum Deposited Nitrogen-Doped Vertically Aligned Carbon Nanofibers as Methanol Tolerant Catalyst for Oxygen Reduction Reaction with Improved Durability

Ayyappan Elangovan,Bin Liu,Jiayi Xu,Jun Li,Sabari Rajendran,Archana Sekar

doi:10.3390/applnano2040022

Ayyappan Elangovan, Bin Liu + Show 4 more

Open Access

https://doi.org/10.3390/applnano2040022

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Journal: Applied Nano	Publication Date: Oct 17, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Kansas State University

Abstract

Nitrogen doping in carbon materials can modify the employed carbon material’s electronic and structural properties, which helps in creating a stronger metal-support interaction. In this study, the role of nitrogen doping in improving the durability of Pt catalysts supported on a three-dimensional vertically aligned carbon nanofiber (VACNF) array towards oxygen reduction reaction (ORR) was explored. The nitrogen moieties present in the N-VACNF enhanced the metal-support interaction and contributed to a reduction in the Pt particle size from 3.1 nm to 2.3 nm. The Pt/N-VACNF catalyst showed better durability when compared to Pt/VACNF and Pt/C catalysts with similar Pt loading. DFT calculations validated the increase in the durability of the Pt NPs with an increase in pyridinic N and corroborated the molecular ORR pathway for Pt/N-VACNF. Moreover, the Pt/N-VACNF catalyst was found to have excellent tolerance towards methanol crossover.

Highlights

Platinum (Pt) nanoparticles (NPs) supported on amorphous carbon (Pt/C) are currently considered to be an effective catalyst for oxygen reduction reaction (ORR) with sluggish reaction kinetics
We explored an N-doped three-dimensional vertically aligned carbon nanofiber (VACNF) array as the catalyst support for ORR
As the VACNFs were plasma annealed, the NH3 plasma started to etch the sidewalls of carbon fibers confirmed from the decrease in diameter

Summary

Introduction

Platinum (Pt) nanoparticles (NPs) supported on amorphous carbon (Pt/C) are currently considered to be an effective catalyst for oxygen reduction reaction (ORR) with sluggish reaction kinetics. The performance of Pt/C deteriorates in long-term operations due to the agglomeration or dissolution of Pt NPs [2]. Another factor that affects long-term performance is the oxidation of the underlying carbon support, i.e., carbon corrosion [3]. Pt on the surface can further catalyze the oxidation of carbon and thereby increasing the agglomeration or dissolution of Pt NPs [7]. To address these issues, various reports have recommended reducing the Pt loading or replacing it completely with non-noble metal catalysts. When the Pt loading is reduced, it is very challenging to maintain the catalytic activity and durability

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