Titanium\u2013tantalum oxide as a support for Pd nanoparticles for the oxygen reduction reaction in alkaline electrolytes

Cinthia Alegre,Vincenzo Baglio,Esterina Modica,Stefania Siracusano,Antonino S Aricò

doi:10.1007/s40243-018-0114-z

Abstract

We report a facile synthetic method for the preparation of titanium–tantalum oxide by means of a modified Adam’s method. This new method allowed obtaining Ti0.8Ta0.2O2 with a high surface area (234 m2 g−1), to be used as catalyst support for Pd nanoparticles. Cyclic voltammetry and linear sweep voltammetry measurements confirm the noticeable oxygen reduction reaction (ORR) activities of the Pd/Ti0.8Ta0.2O2 electrocatalyst in alkaline electrolytes, along with a high-selectivity towards a 4e− pathway. The good ORR performance for the Pd/Ti0.8Ta0.2O2 could arise from both the strong metal-support interaction and the contribution of the Ti0.8Ta0.2O2 in facilitating the ORR process, acting as co-catalyst. However, the stability of this catalyst seems insufficient for practical applications.

Highlights

Oxygen reduction is the most challenging electrochemical reaction for many electrochemical devices, such as fuel cells and metal-air batteries [1,2,3,4,5]
Titanium–tantalum oxides were synthesized by the Adams fusion method using the procedure modified by Marshall [46, 47]. TiCl4 (98%, Fluka) and TaCl5 (99.8%, SigmaAldrich) metal precursors were added to isopropanol (99.5%, Sigma-Aldrich) to obtain a total metal concentration of 0.08 M
Pd nanoparticles were supported on the as-prepared Ti0.8Ta0.2O2 and studied as a catalyst for the oxygen reduction reaction in alkaline media

Summary

Introduction

Oxygen reduction is the most challenging electrochemical reaction for many electrochemical devices, such as fuel cells and metal-air batteries [1,2,3,4,5]. The high potential of this reaction (1.23 V vs reversible hydrogen electrode, RHE) forces the use of highly active and stable catalysts, being Pt-based ones the most employed [6,7,8,9,10] It is widely known the high cost of this metal; several strategies are sought to replace it [11,12,13]. TiO2 has been recognized as a versatile material, easy to produce and with a wide variety of applications (solar cells, degradation of organic pollutants, electrocatalysts supports, etc.) [31,32,33,34,35] It features relatively low cost, non-toxicity, photostability, and inertness [31, 34].

Methods

Results

Conclusion