Singlet Oxygen From Lattice Oxygen‐Adsorbate Hybridization Drives Highly Selective Electrooxidation of Methallyl Alcohol to Methacrolein

ABSTRACT Selective oxidation of methallyl alcohol (MAO) to methacrolein (MAC) is crucial yet challenged by C═C cleavage and overoxidation in both thermochemical and radical‐mediated routes. Herein, we report a Mn‐doped NiMoO 4 catalyst anchored on partially oxidized copper‐foam (M‐NMO/Cu 2+1 O/CF) achieves unprecedented 100% selectivity and Faradaic efficiency for MAO to MAC at a record production rate of 1776 µmol cm −2 h −1 (420 C,1.0 M K 2 CO 3 , 1.62 V vs. RHE). The catalyst synergizes lattice‐oxygen mechanism (LOM) with adsorbate‐evolution mechanism (AEM) to generate singlet oxygen ( 1 O 2 ). This electrophilic 1 O 2 dominates the selective oxidation of Cα–OH in MAO, preserving its C═C bond via preferential α‐hydrogen abstraction. Isotope labeling (H 2 18 O) and operando Fourier‐transform infrared spectroscopy (FT‐IR) reveal that 1 O 2 is generated primarily from lattice‐oxygen through critical peroxide‐like M–O–O intermediates, with a secondary contribution from adsorbed water. Density functional theory (DFT) reveals Mn‐induced asymmetric d‐band engineering concurrently lowers the LOM barrier and raises the AEM barrier at Ni centers, establishing a Ni‐governed, LOM‐dominant dual‐pathway for 1 O 2 generation. The catalyst further enables general furfuryl and benzyl alcohol oxidation, and scale‐up in a flow electrolyzer achieves 90% MAO conversion. This work establishes an asymmetric electronic modulation strategy for in situ generation of singlet oxygen via peroxide‐like intermediates, enabling highly selective electrooxidation of alcohols.