Structured Pd–Cu/NaY Catalyst for Industrial Syngas to DMC: Enhanced Stability and Mechanism

ABSTRACT A structured, chloride‐free Pd–Cu/NaY catalyst was developed for the direct synthesis of dimethyl carbonate (DMC) from syngas‐derived methyl nitrite and CO. The NaY zeolite support stabilizes Pd(II) species via strong electrostatic interactions, while Cu addition enhances durability by suppressing Pd reduction and aggregation, as confirmed by H 2 ‐TPR and TEM. Using shaped spherical supports improves DMC selectivity by limiting methyl nitrite decomposition side reactions through diffusion constraints. Under optimized conditions (CO/MN = 1/6, 120°C), the catalyst achieves a DMC space‐time yield of 669 g·kg −1 ·h −1 with high selectivity. A 1000 h stability test shows sustained activity above 550 g·kg −1 ·h −1 after an initial run‐in period. In situ DRIFTS studies identify the ligand exchange step as rate‐determining and elucidate the full reaction pathway. This robust catalytic system demonstrates strong potential for pilot‐scale and industrial syngas‐to‐DMC processes.