ABSTRACT This study elucidates the crucial role of 2‐cyanopyridine as a dehydrating agent in altering the catalytic mechanism of praseodymium‐doped ceria (Pr–CeO 2 ) for ethylene carbonate (EC) synthesis from ethylene glycol (EG) and CO 2 . In the presence of 2‐cyanopyridine, the Pr–CeO 2 catalyst achieved an exceptional EC yield of 99.9% and a high turnover frequency (TOF) of 58.1 mmol g −1 h −1 . Remarkably, removing 2‐cyanopyridine led to a 95.4% decrease in TOF, yielding only 2.71 mmol g −1 h −1 . Mechanistic studies demonstrate that 2‐cyanopyridine shifts the active sites from moderate‐strength acid–base pairs to weak acid–base sites, leading to divergent catalytic pathways. Comprehensive characterization confirms that 2‐cyanopyridine promotes surface site modification and intermediate transformation, thereby significantly reducing the activation energy for EC formation. This work provides a strategic basis for optimizing dehydrating agents in catalytic carbonylation of alcohols with CO 2 .
Li et al. (2026) studied this question.