High performance of the novel Pd-CeO_(2-NR)/C (cerium oxide nanorods) nanocatalyst for the oxidation of C1, C2 and C3 organic molecules for fuel cells applications

摘要

Cerium oxide nanorods treated at 200 (CeO2-NR2) and 400 degrees C (CeO2-(NR4)) were used to synthesize of Pd CeO2-(NR2)/C and Pd CeO2-(NR4)/C nanocatalysts to promote the Methanol, Ethanol, Ethylene Glycol and Glycerol Oxidation Reactions (MOR, EOR, EGOR and GOR, respectively). The crystalline nanocatalysts had morphology of agglomerated Pd nano particles dispersed on Vulcan and on the nanorods as well. The polarization curves in 0.5 M KOH showed that the catalytic activity decreases in all reactions in the order Pd CeO2-NR4/C Pd CeO2-(NR2)/C Pd/C, which confirmed the synergetic effect of the nanorods on the catalytic behavior of Pd, particularly after heat treatment at 400 degrees C. The highest mass current density has been obtained from the EGOR (jf = 6661 mA mgpj) with the Pd-CeO2-(NR4)/C nanocatalyst, which catalyzed the reaction with an onset potential (E(onse)t) of -0.26 V/SHE. Meanwhile, the EOR was promoted with the most negative E-onset (-0.40 V/SHE), delivering 5719 mA mg(Pd)(-1), also using Pd CeO2-(NR4)/C. Therefore, considering electrocatalysis parameters for fuel cells applications, the oxidation of C2H6O2 and C2H5OH showed advantages using Pd CeO2-NR4/C. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.