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, CeO 2 nanorods were thermally annealed in an NH 3 atmosphere and subsequently employed as supports for Pd nanoparticles toward the formic acid oxidation reaction (Pd/N-CeO 2 ). The NH 3 treatment induced structural collapse and incorporation of N into CeO 2, leading to abundant vacancies, defect formation, and electronic structure modulation. As a result, the Pd/N-CeO 2 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/CeO 2 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-CeO 2 synergy. Moreover, the Pd/N-CeO 2 catalyst demonstrated accelerated reaction kinetics and improved charge transfer ability compared with Pd/CeO 2, confirming the effective role of N-doping into CeO 2 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.