*2.4. Electrochemical Test*

All electrochemical tests were performed in a conventional three-electrode system (Ivium Stat, Ivium Technologies, Eindhoven, Netherlands). The obtained Pd–Pt bimetallic catalyst/carbon paper electrode was used as the working electrode. A platinum plate and a saturated calomel electrode (SCE) served as the counter and the reference electrodes, respectively. The cyclic voltammetry (CV) curves of the obtained Pd–Pt bimetallic catalysts were tested in a N2-saturated aqueous solution of 0.5 M H2SO4 at a scan rate of 50 mV s<sup>−</sup>1. The voltammetric curves of the obtained Pd–Pt bimetallic catalysts towards FAOR were recorded in an aqueous solution of 0.5 M H2SO4 and 0.5 M HCOOH at a scan rate of

50 mV s<sup>−</sup>1. The chronoamperometry curves of the obtained Pd–Pt bimetallic catalysts were recorded in an aqueous solution of 0.5 M H2SO4 and 0.5 M HCOOH at 0.15 V for 3000 s.
