Palladium (Pd)-based catalysts, as an ideal alternative to platinum (Pt) for oxygen reduction reaction (ORR), have been the focus of recent research because of their comparable catalytic activities, low cost, and abundant resource. Unfortunately, Pd is easy to suffer from agglomeration because of the decrease of their excessive metal surface free energy at elevated temperature, dramatically reducing their catalytic activities for ORR. Herein, we report a facile in-situ self-assembly strategy coupled with the annealing method to synthesize the well-dispersed Pd nanoparticles on nitrogen-doped mesoporous carbon spheres (Pd-NMCS) catalysts, and analyze the catalytic activities for ORR. More importantly, the nitrogen atoms in the NMCS can expose more basic/catalytic sites that can coordinate with Pd nanoparticles to form the strong Pd-N interactions, which can not only tightly anchor Pd nanoparticles but also be advantageous to show outstanding stability and good resistance to methanol crossover. As expected, the obtained Pd-NMCS exhibit good ORR catalytic activities, desirable reaction kinetics, excellent stability, as well as better methanol tolerance, which may offer potential for the practical application of fuel cells.

钯 (Pd) 基催化剂作为氧还原反应 (ORR) 中铂 (Pt) 的理想替代品，因其具有可比的催化活性、低成本和丰富的资源而成为近期研究的重点。不幸的是，Pd 容易发生团聚，因为它们在高温下过多的金属表面自由能降低，大大降低了它们对 ORR 的催化活性。在此，我们报告了一种简便的原位自组装策略，结合退火方法在氮掺杂介孔碳球（Pd-NMCS）催化剂上合成分散良好的 Pd 纳米粒子，并分析了 ORR 的催化活性。更重要的是，NMCS 中的氮原子可以暴露更多的碱性/催化位点，这些位点可以与 Pd 纳米粒子配合形成强烈的 Pd-N 相互作用，它不仅可以牢固地锚定 Pd 纳米粒子，而且有利于表现出出色的稳定性和良好的抗甲醇渗透性。正如预期的那样，所获得的 Pd-NMCS 表现出良好的 ORR 催化活性、理想的反应动力学、优异的稳定性以及更好的甲醇耐受性，为燃料电池的实际应用提供了潜力。