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

초록

Herein, a hybrid support of Nb-doped TiO 2 and carbon nanotubes (Nb x TO@CNT, x = Nb wt%) was successfully prepared by a facile hydrothermal method. Controlling the annealing temperature to form either anatase (ANb x TO@CNT) or rutile (RNb x TO@CNT) changed the effect of the Nb dopant in the TiO 2 structure. The Pt/ RNb 10 TO@CNT electrocatalyst exhibits excellent oxygen reduction reaction activity and durability (E onset : 0.945 V vs. RHE; E 1/2 : 0.888 V vs. RHE; j L : -6.260 mA cm -2 ). Theoretical calculations predicted that the synergetic effect of Pt/RNb 10 TO@CNT improves the electrochemical performance. The strong metal-support interaction (SMSI) effect and the formation of oxygen vacancies due to the increased amount of Ti 3+ 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/RNb 10 TO@CNT (1.913 A cm -2 at 0.6 V) and low current degradation (6.3%) under identical conditions.

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