Enhancing the electrocatalytic methanol oxidation activity of Pd nanoparticles via promoter modulation

Rational modulation of metal-support interaction (MSI) is pivotal yet challenging for developing high-performance electrocatalysts. Herein, we demonstrate a promoter engineering strategy to precisely tune the N configuration in ZIF-8-derived carbon supports for boosting Pd-catalyzed methanol oxidation reaction (MOR). Structurally diverse organic promoters (urea, dicyandiamide, sucrose, xylitol) impregnated in ZIF-8 pores regulate pyrolysis behavior, yielding N-doped carbons with optimized porosity, graphitization, and N-configuration. Among them, urea-modified support (NC–U) demonstrates the highest surface area (925 m 2  g −1 ) and graphitic-N content (40.4 %), facilitating uniform dispersion of ultrasmall Pd nanoparticles (2.71 nm) and electron transfer to enrich metallic Pd 0 (75.2 %). The resulting Pd/NC-U delivers exceptional MOR activity (5570.7 mA·mg −1 Pd ) and stability (87.4 % retention after 500 cycles), outperforming unmodified Pd/NC by 1.32-fold. Besides, operando SERS reveals a CO-free pathway on all catalysts, with Pd/NC-U initiating HCO 3 − /CO 3 2− formation at the lowest potential (0.4 V vs. RHE). This work establishes promoter-mediated N-configuration control as a robust route to tailor MSI for efficient alcohol electrooxidation.