SiC nanocrystals as Pt catalyst supports for fuel cell applications

Rajnish Dhiman,Shuang M Andersen,Per Morgen,Eivind M Skou,Erik Johnson

doi:10.1039/c3ta10238f

Rajnish Dhiman, Shuang M Andersen + Show 3 more

Open Access

https://doi.org/10.1039/c3ta10238f

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Abstract

A robust catalyst support is pivotal to Proton Exchange Membrane Fuel Cells (PEMFCs) to overcome challenges such as catalyst support corrosion, low catalyst utilization and overall capital cost. SiC is a promising candidate material which could be applied as a catalyst support in PEMFCs. SiC nanocrystals are here synthesized using nano-porous carbon black (Vulcan® XC-72) as a template using two different reactions, which result in particle sizes in the ranges of 50–150 nm (SiC-SPR) and 25–35 nm (SiC-NS). Pt nano-catalysts of size 5–8 nm and 4–5 nm have successfully been uniformly deposited on the nanocrystals of SiC-SPR and SiC-NS by the polyol method. The SiC substrates are subjected to an acid treatment to introduce the surface groups, which help to anchor the Pt nano-catalysts. These SiC based catalysts have been found to have a higher electrochemical activity than commercially available Vulcan based catalysts (BASF & HISPEC). These promising results signal a new era of SiC based catalysts for fuel cell applications.

Highlights

The Proton Exchange Membrane Fuel Cells (PEMFCs) are, in combination with the easy availability of hydrogen or methanol, considered to be among the most promising clean energy providers in the near future for both stationary and portable power supplies.[1]
There is a small shoulder observed at 33.6 for synthesized by reaction with SiO (SiC-NS), which corresponds either to the traces of a-SiC31 or it may be the characteristic of stacking faults in b-SiC.[28]
The most essential achievements of the present work are the successful synthesis of SiC nanocrystals; the deposition of the Pt nano-catalyst on nano-scale SiC supports using the polyol

Summary

Introduction

The Proton Exchange Membrane Fuel Cells (PEMFCs) are, in combination with the easy availability of hydrogen or methanol, considered to be among the most promising clean energy providers in the near future for both stationary and portable power supplies.[1] The catalyst support material is a vital component of PEMFCs, and it should be engineered to reduce the demand for expensive noble metal catalysts (for example, platinum). The conventionally used carbon support materials are susceptible to oxidization under the chemical and electrochemical conditions at both electrodes in the fuel cell.[2,3] This corrosive environment is even made more aggressive with the catalytic effect of the noble metal particles. With corrosion of the carbon support the nano-sized noble metal particles may fall off leading to a loss of catalytic activity and decreasing cell performance.[4,5] Generally, a good catalyst support material for fuel cells should have high chemical/electrochemical durability, high thermal stability, high mechanical

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