N-Doped CeO ₂ Nanorods as Supports of Pd Nanoparticles for Formic Acid Electrooxidation

Effective structural regulation of supports is crucial for the development of advanced supported catalysts. Herein, CeO2 nanorods were thermally annealed in an NH3 atmosphere and subsequently employed as supports for Pd nanoparticles toward the formic acid oxidation reaction (Pd/N-CeO2). The NH3 treatment induced structural collapse and incorporation of N into CeO2, leading to abundant vacancies, defect formation, and electronic structure modulation. As a result, the Pd/N-CeO2 catalyst exhibited superior catalytic performance, achieving a peak mass activity of 886.5 mA mg–1, which was 2.72 and 1.74 times higher than those of Pd/CeO2 and Pd/C, respectively. CO stripping experiments further confirmed its enhanced tolerance to CO-like intermediates, evidencing the weakened CO adsorption by the Pd/N-CeO2 synergy. Moreover, the Pd/N-CeO2 catalyst demonstrated accelerated reaction kinetics and improved charge transfer ability compared with Pd/CeO2, confirming the effective role of N-doping into CeO2 in boosting the intrinsic activity of Pd. This study highlights the effectiveness of oxide support surface engineering and offers a promising strategy for the rational design of highly efficient Pd-based electrocatalysts.