Thin layer vs. nanoparticles: Effect of SnO2 addition to PtRhNi nanoframes for ethanol oxidation reaction

When designing catalysts for direct ethanol fuel cell applications (DEFC), four main parameters must be considered: shape, structure, size, and chemical composition. According to this knowledge, it is assumed that polyhedral hollow Pt-based nanoframes, with the addition of Rh and SnO2 with a size below 50 nm, could be a promising nanocatalysts for the anode of DEFC. In this work, two different PtRhNi/SnO2 nanoframes-based catalysts are obtained. First consists of PtRhNi nanoframes covered with small, about 3 nm, SnO2 nanoparticles (PtRhNi/SnO2 NPs); and second is the PtRhNi nanoframes covered with a thin and incomplete SnO2 layer (PtRhNi/SnO2 TL). Both nanocatalysts were tested toward ethanol oxidation reaction (EOR) and show higher activity in comparison to PtRhNi nanoframes without SnO2 (PtRhNi NFs) addition and commercially used Pt nanoparticles. Especially, the electrochemical durability and stability of obtained nanocatalysts were tested. It was shown that both PtRhNi/SnO2 nanoframes-based catalysts develop similar mass and specific activity, as well as nearly the same onset potential, but their stability is significantly different. It turns out, that catalyst based on PtRhNi nanoframes covered with a thin SnO2 layer is susceptible to degradation, while the catalyst consisting of PtRhNi nanoframes covered with SnO2 nanoparticles is much more durable and could be used as an efficient catalyst toward EOR. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

When designing catalysts for direct ethanol fuel cell applications, the shape, structure, size, and chemical composition must be considered. This study explores the use of PtRhNi/SnO2 nanoframes as potential nanocatalysts for the anode of DEFC. The nanocatalysts showed higher activity and durability compared to PtRhNi nanoframes without SnO2 addition and commercially used Pt nanoparticles.