An alternate aqueous phase synthesis of the Pt3Co/C catalyst towards efficient oxygen reduction reaction

Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction (ORR) for the application in low temperature fuel cells and beyond, thus their facile and green synthesis is highly demanded. Herein we initially report an alternate aqueous phase one-pot synthesis of such catalysts (containing nominally ca. 20 wt.% Pt) based on dimethylamine borane (DMAB) reduction. The as-obtained electrocatalyst (denoted as Pt 3 Co/C-DMAB) is compared with the ones obtained by NaBH 4 and N 2 H 4 ·H 2 O reduction (denoted as Pt 3 Co/C-NaBH 4 and Pt 3 Co/C-N 2 H 4 ·H 2 O, respectively) as well as a commercial Pt/C, in terms of the structure and electrocatalytic property. It turns out that Pt 3 Co/C-DMAB exhibits the highest ORR performance among all the tested samples in an O 2 -saturated 0.1 mol/L HClO 4 , with the mass activity (specific activity) ca. 4 (6) times as large as that for Pt/C. After 10000 cycles of the accelerated degradation test, the half-wave potential for ORR on Pt 3 Co/C-DMAB decreases only by 4 mV, in contrast to 24 mV for that on Pt/C. Pt 3 Co/C-NaBH 4 or Pt 3 Co/C-N 2 H 4 ·H 2 O shows a specific activity comparable to that for Pt 3 Co/C-DMAB, but a mass activity similar to that for Pt/C. ICP-AES, TEM, XRD and XPS characterizations indicate that Pt 3 Co nanoparticles are well-dispersed and alloyed with a mean particle size of ca. 3.4 plusmn; 0.4 nm, contributing to the prominent electrocatalytic performance of Pt 3 Co/C-DMAB. This simple aqueous synthetic route may provide an alternate opportunity for developing efficient practical electrocatalysts for ORR. Pt 3 Co/C with well-controlled size, dispersion and alloying degree was obtained using aqueous phase synthesis with DMAB being the reductant, exhibiting excellent electrocatalytic activity and durability for ORR.