Boosting the Oxygen Reduction Electrocatalytic Performance of Nonprecious Metal Nanocarbons via Triple Boundary Engineering Using Protic Ionic Liquids

The oxygen reduction reaction (ORR) in aqueous media plays a critical role in sustainable and clean energy technologies such as polymer electrolyte membrane and alkaline fuel cells. In this work, we present a new concept to improve the ORR performance by engineering the interface reaction at the electrocatalyst/electrolyte/oxygen triple-phase boundary using a protic and hydrophobic ionic liquid and demonstrate the wide and general applicability of this concept to several Pt-free catalysts. Two catalysts, Fe–N codoped and metal-free N-doped carbon electrocatalysts, are used as a proof of concept. The ionic liquid layer grafted at the nanocarbon surface creates a water-equilibrated secondary reaction medium with a higher O2 affinity toward oxygen adsorption, promoting the diffusion toward the catalytic active site, while its protic character provides sufficient H+/H3O+ conductivity, and the hydrophobic nature prevents the resulting reaction product water from accumulating and blocking the interface. Our strategy brings obvious improvements in the ORR performance in both acid and alkaline electrolytes, while the catalytic activity of FeNC-nanocarbon outperforms commercial Pt–C in alkaline electrolytes. We believe that this research will pave new routes toward the development of high-performance ORR catalysts free of noble metals via careful interface engineering at the triple point.

Bibliographic Details

Main Authors:	Qiao, Mo, Álvarez Ferrero, Guillermo, Fernández Velasco, Leticia, Vern Hor, Wei, Yang, Yan, Luo, Hui, Lodewyckx, Peter, Fuertes Arias, Antonio Benito, Sevilla Solís, Marta, Titirici, María-Magdalena
Format:	artículo biblioteca
Published:	American Chemical Society 2019
Subjects:	non-precious metal catalysts, electrocatalysis, triple phase boundary, interface reaction, oxygen reduction reaction,
Online Access:	http://hdl.handle.net/10261/223514
Tags:	Add Tag No Tags, Be the first to tag this record!