T.H.P. Vu, T.N.H. Le, B.T.T. Nguyen, V.M. Tran, T.G.H. Nguyen, M.L.P. Le, V.T. Le, T.P.T. Nguyen
Vietnam National University - Ho Chi Minh City, VN
alcohol oxidation, carbon support, electrocatalyst, platinum, nano particles
Platinum is the most effective catalyst for electrode reactions in fuel cells. However, challenges for this catalyst are its scarcity and high cost, as well as the poisoning by the intermediates of the fuel oxidation, such as CO. Using nanoscale metallic or bimetallic electrocatalytic materials is supposed to facilitate the cost reducing and to increase the catalytic activity. In this work, nanoscale bimetallic PtNi catalysts with total metal loadings of 20 wt.% supported on carbon Vulcan XC-72R and carbon nanotube (CNT) have been synthesized by the polyol reduction method under ultrasonic irradiation using ethylene glycol (EG) as the reducing reagent. The morphology, structure and specific area of synthesized materials (PtxNiy/C) were analyzed by TEM, nitrogen adsorption (BET) and XRD. The electrocatalytic activity of PtxNiy/C and commercial Pt/C_com catalysts for alcohol oxidation was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The electrochemically active surface area (ECA) calculated from CVs for PtxNiy/VC catalysts with different of Pt to Ni atom ratio revealed that the catalyst with 1:1 Pt to Ni ratio has the highest ECA. Among the PtxNiy/CNT catalyst, the highest ECA was found for Pt2Ni1/CNT sample. The most completeness of methanol oxidation occurred at the Pt3Ni1/VC electrode.