The High‐Performance Bifunctional Catalyst Pd/Ti₃C₂T_<i>x</i>–Carbon Nanotube for Oxygen Reduction Reaction and Hydrogen Evolution Reaction in Alkaline Medium

Abstract

The metal–support interaction offers electronic, compositional, and geometric effects that can enhance the catalytic activity and stability. Herein, a performance‐enhanced electrocatalyst of Pd nanoparticles loaded on a hybrid catalytic support comprised of MXene (Ti 3 C 2 T x ) and carbon nanotube (CNT) is demonstrated. Such a hybrid catalyst enhances durability and improves both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) activities compared with the Pd/C catalysts. The mass specific activity and specific activity of the Pd/Ti 3 C 2 T x –CNT catalyst are 4.4 and 3.3 times that of Pd/C for ORR, respectively. The peak power density of a alkaline anion exchange membrane fuel cell (AAEMFC) based on the Pd/Ti 3 C 2 T x –CNT (1:2) cathode achieves 48 mW cm −2 at 60 °C. Furthermore, Pd/Ti 3 C 2 T x –CNT also exhibits rapid HER kinetics with a low overpotential of 158 mV at 10 mA cm −2 and a Tafel slope of 50 mV dec −1 . Pd/Ti 3 C 2 T x –CNT also provides good stability after 1000 cycles. These remarkable catalytic performances are attributed to the role of Ti 3 C 2 T x and CNT by enhancing the catalytic activity surface area and rapid mass/charge transfer due to the synergistic effect between Pd and Ti 3 C 2 T x –CNT.