Silicon-based carbonaceous electrocatalysts for oxygen reduction and evolution properties in alkaline conditions

Abstract

In this contribution, new electrocatalyst materials, namely silicon-multiwalled carbon nanotubes (Si/MWCNTs), nitrogendoped multiwalled carbon nano-tubes (Si/NCNTs), and silicon-carbon black (Si/CB), were developed and characterized in an effort to investigate less expensive and more efficient alternatives to Pt-based catalysis for energy storage cells applications. The role of structural behavior of obtained specimens and corresponding electrochemical performances were characterized through X-ray diffraction and scanning electron microscopy, while cyclic voltammetry and electrochemical impedance spectroscopy were analyzed for electrochemical measurements and evaluation of oxygen evolution reaction (OER) along with oxygen reduction reaction (ORR). The electrochemical studies have shown that these materials exhibit reasonable performance for both the ORR and the OER. The findings concluded that the Si/CB base catalyst has shown both OER and ORR activities in comparison to Si/MWCNTs and Si/NCNTs where only ORR performance was monitored. However, Si/NCNTs have shown much higher ORR activity compared to the others. This work highlights the comparison of three possible alternative materials as a potential catalyst to develop optimum alternatives of Pt-free catalysts for fuel cell and lithium-based battery systems.

The use of silicon in the membrane electrode assembly of fuel cells

“…observed that that the ORR activity in alkaline medium of Si‐CNT was higher than that of pure CNT. The ORR activity of Si‐ and N‐codoped CNT was higher than that of single doped CNT [180,181] …”

“…Finally, the ORR on Si-CNT was experimentally evaluated in some works. [16,170,180,181] Fu et al [168] and Gonzalez et al [170] observed that that the ORR activity in alkaline medium of Si-CNT was higher than that of pure CNT. The ORR activity of Siand N-codoped CNT was higher than that of single doped CNT.…”

“…Co‐doping with N and less electronegative Si causes structural distortions as well as the modification of charge and spin densities in the graphene structure due to different electronic and chemical properties of Si−C and Si−N bonds. Finally, the ORR on Si‐CNT was experimentally evaluated in some works [16,170,180,181] . Fu et al [168] .…”