Durable Platinum‐Based Electrocatalyst Supported by Multiwall Carbon Nanotubes Modified with CeO2

Abstract

AbstractThe stability of a carbon support is especially essential for oxygen reduction reaction (ORR) electrocatalysts in fuel cells. The state‐of‐the‐art support, generally active carbons, usually have poor corrosion resistance and weak interaction with noble metals, leading to degradation of electrocatalyst performance. Herein, a composite electrocatalyst support denoted CeO2/MWNT, combining high corrosion resistance and strong interaction with platinum, was fabricated through ceria deposited on multiwall carbon nanotubes (MWNTs). On the one hand, high electronic conductivity, medium surface area, and abandoned surface functional groups of MWNTs guarantee fine dispersion and performance of platinum. On the other hand, high corrosion resistive MWNTs and strong interactions between platinum and CeO2 prevent the platinum from degrading. The durability of the electrocatalyst and support are evaluated, referring to the NREL standard. After accelerated testing, the mean particle size of Pt‐CeO2/MWNT increases from 3.1 to 3.5 nm, whereas the loss of electrochemical surface area and specific activity are 14.7 and 9.2 %, respectively, which are much lower than those of commercial Pt/C, which uses activated carbon as the support.