Highly durable Pt electrocatalyst on a hybrid support for boosting the sustainability of polymer electrolyte membrane fuel cells

• Published in: International journal of hydrogen energy 2024-07, Vol.74, p.392-403
• Main Authors: Yoon, Yong Hoon, Lee, Seungjun, Kim, Minkyu, Park, Jungwoo, Son, Hyeonwook, Kim, Moonsu, Tak, Yongsug, Lee, Gibaek
• Format: Article
• Language: English
• Subjects: Electrocatalyst; Hybrid materials; Oxygen reduction reaction; Polymer electrolyte membrane fuel cells; Titanium dioxide
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.06.150

Herein, a hybrid support of Nb-doped TiO2 and carbon nanotubes (NbxTO@CNT, x = Nb wt%) was successfully prepared by a facile hydrothermal method. Controlling the annealing temperature to form either anatase (ANbxTO@CNT) or rutile (RNbxTO@CNT) changed the effect of the Nb dopant in the TiO2 structure. The Pt/RNb10TO@CNT electrocatalyst exhibits excellent oxygen reduction reaction activity and durability (Eonset: 0.945 V vs. RHE; E1/2: 0.888 V vs. RHE; jL: −6.260 mA cm−2). Theoretical calculations predicted that the synergetic effect of Pt/RNb10TO@CNT improves the electrochemical performance. The strong metal-support interaction (SMSI) effect and the formation of oxygen vacancies due to the increased amount of Ti3+ was observed. Band-gap reorganization by the distortion of electronic structures was further confirmed by UV–visible spectrometry. Single-stack polymer electrolyte membrane fuel cell measurements showed the highly improved current density of Pt/RNb10TO@CNT (1.913 A cm−2 at 0.6 V) and low current degradation (6.3%) under identical conditions. We report a Nb-doped rutile TiO2@CNT hybrid catalyst support prepared by a facile method, namely RNb10TO@CNT, which exhibits enhanced activity and ultra-durability of Pt towards ORR by improved SMSI effect caused by Nb doping. [Display omitted] •Nb-doped rutile TiO2@CNT hybrid support was designed by a facile synthesis process.•Pt/Nb-doped rutile TiO2@CNT ORR catalyst showed reasonable activity and durability.•Nb doping not only controlled electronic structures but also enhanced SMSI effect.•Significantly improved sustainability was exhibited in a single-stack PEMFC cell.