Niobium Enhances Electrocatalytic Pd Activity in Alkaline Direct Glycerol Fuel Cells

Abstract

Abstract Pd x Nb y /C binary electrocatalysts supported on Printex 6 L carbon black were prepared by using an adapted chemical reduction method with sodium borohydride. The electrocatalysts were characterized by using SEM, TEM, XRD, EDS, ICP‐MS, water contact angle and Raman spectroscopy. The best performance for the alkaline direct glycerol fuel cell (ADGFC) was obtained by using Pd 1 Nb 1 /C, which yielded a maximum power density of 27 mW cm −2 at 70 °C. Residues of products formed from the glycerol oxidation were analyzed by using FT‐Raman and high‐performance liquid chromatography (HPLC). The Pd 1 Nb 1 /C electrocatalyst exhibited a more negative onset potential for the CO oxidation reaction and a higher conversion rate of glycerol to carbonate. We suggest that the higher hydrophilicity, higher degree of disorder, and bifunctional effects enhanced the electrocatalytic activity of Pd, as Nb facilitated the oxidation of adsorbed CO in Pd and increased the transfer rate of electron from Pd to carbon black support Therefore, Nb is a promising co‐catalyst for Pd‐based electrocatalysts for ADGFCs.