Carbon Dioxide Activation and Organic Transformations Over ppm‐Level Mg‐Doped ZnO: A Facile Route to the N‐Formylation of Amines Under Molecular Hydrogen

ABSTRACT Rising atmospheric CO 2 concentration drives climate change, making CO 2 conversion into value‐added chemical a central challenge in chemistry. Here, we reported the synthesis of a ppm‐level Mg‐doped ZnO (Mg–ZnO) heterogeneous catalyst containing 118 ppm Mg (0.0118 wt.%), as determined by ICP‐OES, prepared via a facile coprecipitation method and comprehensively characterized to confirm its structural, electronic, morphological, and compositional integrity. At an optimal Mg loading, the catalyst exhibits abundant surface basic sites, high surface area, and a robust heterostructure. The catalyst efficiently facilitates two CO 2 utilization reactions, namely the selective N‐formylation of amine under CO 2 /H 2 in methanol and the water‐mediated synthesis of quinazoline‐2,4‐diones from 2‐aminobenzonitrile under CO 2 , demonstrated broad substrate scope across 18 structurally diverse substrate, delivering a TON of 1.89 × 10 4 and TOF of 632 h − 1 , outperforming reported noble metal systems. Further, the catalyst retained >60% activity over six cycles, conforming to excellent stability and recyclability. This noble metal free approach eliminates toxic reagents, achieves a high atom economy, and is aligned with green chemistry principles for sustainable CO 2 valorization.