Bimetallic PtIr nanoalloy on TiO2-based solid solution oxide with enhanced oxygen reduction and ethanol electro-oxidation performance in direct ethanol fuel cells†
Elevating the electrocatalytic performance of both cathode and anode catalysts is critical to the advancement and widespread utilization of low-temperature fuel cells. Herein, we report an effective Pt3Ir/Ti0.7W0.3O2 catalyst for the oxygen reduction reaction (ORR) and ethanol electro-oxidation reaction (EOR) using a facile reduction process. In terms of the ORR, the Pt3Ir/Ti0.7W0.3O2 catalyst shows a specific activity of 0.99 mA cm−2 and a mass activity of 0.802 A mgPt−1, which are 6.72- and 7.22-fold improvements compared to the commercial Pt/C catalyst. The result of the 10 000-cycle accelerated durability test (ADT) under an O2 atmosphere indicates that the impressive ORR stability of the Pt3Ir/Ti0.7W0.3O2 catalyst with a decay of 12.26% in mass activity, against a large decrease of 45.76% for Pt/C (E-TEK). In addition, the Pt3Ir/Ti0.7W0.3O2 catalyst exhibits better EOR performance compared to the Pt/C catalyst with a high mass activity (810.03 mA mgPt−1) along with superior CO-tolerant ability and durability. The improved electrocatalytic performance of the Pt3Ir/Ti0.7W0.3O2 catalyst is attributed to the beneficial effect of alloying Pt with Ir and the merit of the TiO2-based support along with the synergistic effect between the Pt3Ir alloy and Ti0.7W0.3O2 support. These findings can offer a robust catalyst platform for fuel cells, solar cells, and biosensors.