Endowing magnesium single atoms with record-high catalytic performance in dimethyl carbonate synthesis by regulating coordination environment

Magnesium (Mg) derived solid bases are generally considered catalysts with weak or medium basicity and inactive in strong-base-catalyzed reactions. Here we have successfully synthesized Mg single atom catalyst through adjusting coordination environment, which shows record-high activity in strong-base-catalyzed transesterification reaction. Polymer [assembled by 3,5-diamino-1,2,4-triazole and 2,4,6-tris(bromomethyl) mesitylene] derived nitrogen-doped carbon (PNC) was employed as the support and Mg single atom catalyst (Mg₁/PNC) was acquired by a grinding-pyrolysis method. Diverse characterizations and simulated studies unravel that Mg single atoms are incorporated into nitrogen-doped carbon to form a Mg-C₁N₃ motif, which is unlike traditional solid bases where basicity is originated from oxygen atoms. The innovative Mg single atom solid base afforded an unprecedentedly high catalytic performance with a record-breaking yield of 54.2 % in the transesterification process of methanol and ethylene carbonate to generate dimethyl carbonate at 70 °C for 4 h, which surpasses all previously reported state-of-the-art solid base catalysts (2.5–41.5 %). The corresponding turnover frequency (182.9 h⁻¹) exceeds than that of reported solid bases (5.0–128.0 h⁻¹). Additionally, Mg-C₁N₃ architecture inhibited possible loss and aggregation of Mg, ensuring good stability and recyclability. This research might inspire the progress of efficient solid base catalysts with exceptional sources of basicity for diversified applications.