Palladium nanoparticles anchored on MXene-based N-doped porous carbon nanosheets as an advanced electrocatalyst for ethanol oxidation

Pd-based electrocatalysts with advanced activity and durability can greatly accelerate the commercial process of direct ethanol fuel cells (DEFCs). However, Pd nanoparticles (NPs) are easily aggregated and deactivated during the ethanol oxidation reaction (EOR), which will restrict their electrocatalytic efficiency during the long-term running. To solve these problems, we develop new sandwich-like MXene-based N-doped porous carbon (NPCM) through carbonizing and acid etching of ZIF/MXene composite nanosheets. The derived NPCM nanosheets possess a highly ordered nano-porous and N-doped structure, which can be used as competitive catalyst supports to highly disperse Pd NPs and effectively avoid the aggregation and deactivation of Pd NPs. Meanwhile, the as-synthesized Pd/NPCM can offer more activity sites and more space for electrocatalysis reaction, leading to excellent CO tolerance. Thanks to the combination of MXene and ZIF, the designed Pd/NPCM electrocatalyst can offer connected channels for the fast diffusion of reactants and products. Impressively, the Pd/NPCM electrocatalyst exhibits a mass activity of 2237 mA·mgPd−1, which is 1.90 and 6.37 folds that of Pd/ZIF (1179 mA mgPd−1) and Pd/C (351 mA mgPd−1) electrocatalyst, respectively. This work not only explores a novel strategy for preparing advanced electrocatalyst support materials but also opens up their wide applications in DEFCs.