On the effect of non-carbon nanostructured supports on the stability of Pt nanoparticles during voltage cycling: A study of TiO2 nanofibres

Abstract

Electrospun carbon and Nb-doped TiO2 nanofibres (CNFs, TNFs) have been investigated as electrocatalyst supports for polymer electrolyte membrane fuel cells (PEMFC).The optimal Nb doping amount has been identified for TNFs, and thermal treatment of titanium oxide fibres optimised to balance the surface area and electronic conductivity requirements. The most highly conducting material is characterised by a high concentration of surface Ti 3+ and Nb 4+ (and oxygen vacancies). Pt nanoparticles of average diameter of 2.3 nm were loaded onto 10 %at Nb doped-TiO2, retained as the best candidate for further electrochemical analysis, and on CNFs, using a microwave-assisted polyol method. Significantly higher electrochemically active surface area was retained after voltage cycling to 1.2 V for Pt supported on TNF (73 %) than on CNFs, where only 8% of the original ECSA was conserved after 1000 voltammetric cycles. The mass activity was also slightly higher for the titanium oxide based electrodes in the oxygen reduction reaction.

Electrochemical oxygen reduction behaviour of platinum nanoparticles supported on multi-walled carbon nanotube/titanium dioxide composites

“…Pt/Nb-TiO 2 -carbon was used as a cathode material in lowtemperature fuel cell and a good fuel cell performance was observed (peak power density 0.34 W cm À2 ). In a further development, non-carbon ceramic Nb-doped TiO 2 nanofibers were used as Pt catalyst support [89]. This Pt/Nb-TiO 2 material retained a significantly higher ECSA during repetitive potential cycling than Pt deposited on carbon nanofibers.…”

Mixed layered WO3/ZrO2 films (with and without rhodium) as active supports for PtRu nanoparticles: enhancement of oxidation of ethanol

“…Systems of noble metal nanoparticles supported onto high surface area metal oxides are of considerable interest to electrocatalysis [1][2][3]. Among important functions of the support is not only to separate catalytic metal nanoparticles physically in order to diminish their agglomeration and degradation but also to interact beneficially with the metal centers or even with reactants, including the reaction intermediates.…”

Electrospinning of Nanofibers for Energy Applications

“…Electrospun Pt/TiO 2 NFs were also synthesized by electrospinning and the reductive impregnation method, which were used as electrocatalysts and exhibited high activities for methanol oxidation [167]. Electrospun Nb-TiO 2 NFs were investigated as electrocatalyst supports for PEMFCs [168]. The Pt/Nb-TiO 2 NFs showed a high stability after accelerated stress tests, retaining 73% of the electroactive Pt area (the value of Pt/CNFs was 8%).…”