A branch-leaf-like hierarchical MgFe-LDH/CNT-COOH composite as an acid-base synergistic catalyst for efficient transesterification to dimethyl carbonate

MgFe-LDH/CNT-COOH composite with branch-leaf-like architecture is fabricated via in-situ co-precipitation. • MgFe-LDH/CNT-COOH shows better activity and stability compared with various solid base catalysts. • Interfacial Fe–O–C bonds boost Lewis acidity and acid-base synergy. • Interfacial electronic engineering creates acid-base synergy beyond conventional basicity-dominated paradigm. Layered double hydroxides (LDHs) are promising solid base catalysts for the transesterification of ethylene carbonate (EC) with methanol to produce dimethyl carbonate (DMC), but their catalytic efficiency is often limited by severe nanosheet aggregation and insufficient regulation of active sites. Herein, a branch-leaf-like hierarchical MgFe-LDH/CNT-COOH composite was constructed via an in-situ co-precipitation strategy. The optimized composite achieved a DMC yield of 75% with a turnover frequency (TOF) of 116.14 h −1 at 60 °C. Notably, despite its lower total basicity than pristine MgFe-LDH, the composite exhibited significantly enhanced catalytic activity, indicating that the overall basicity alone does not govern the catalytic performance. Synchrotron X-ray absorption spectroscopy and density functional theory calculations revealed that the enhanced activity is closely associated with the formation of interfacial Fe–O–C bonds between MgFe-LDH and CNT-COOH. The interfacial bonding induces electron withdrawal from Fe 3+ centers and shifts the Fe 3d-band center closer to the Fermi level, thereby strengthening Lewis acidity. The enhanced Lewis acid sites facilitate the activation of EC, while the coexisting basic sites promote methanol activation, resulting in efficient acid-base synergistic catalysis. This work demonstrates that interfacial electronic modulation in hierarchical LDH-based composites provides an effective strategy for constructing high-performance acid-base synergistic catalysts. Download: Download high-res image (261KB) Download: Download full-size image