Biomass-rich hydroxylated Mo-W@C with confinement effect and electronic synergistic effect for deep oxidative desulfurization

The surface of the C shell is covered with mesoporous channels, which promotes the occurrence of the confinement effect. • The abundant hydroxyl groups enable the C shell not only to exert physical adsorption but also to cooperate with chemical adsorption. • Both the dual transition metal regulation mechanism and the electron cooperative mechanism can be applied in ODS. • The desulfurization rate (99.53%) can be achieved under the mild reaction condition with less dosages of catalysts and ILs. • EPR analysis and radical scavenging assay experiments confirmed that one type of free radicals acts in the ODS. Common transition metal catalysts have been widely applied in catalytic reaction. However, the shortcomings in electronic regulation mechanism, confinement effect, and synergistic adsorption remain to be urgently addressed. This study designed a dual-transition-metal-based catalyst (Mo-W@C) with a surface rich in hydroxyl functional groups. Its bimetallic active components are obtained through protonation reaction. The C shell is coated on the bimetallic active components through self-assembly and directional anchoring. These procedures reduce the interatomic distance between Mo and W in the bimetallic active component, enhancing the electronic interaction between them. The confinement effect of the C shell accelerates the collision of reaction molecules. Furthermore, the abundant hydroxyl groups on the surface of the C shell facilitate the rapid adsorption of H 2 O 2 . A high sulfur removal rate of Mo-W@C (99.56 %) was achieved under mild reaction conditions (V(ILs) = 0.1 mL, m(catalyst) = 10 mg, V(H 2 O 2 ) = 0.15 mL, 80 °C, 90 min). Moreover, the catalyst still maintained a high desulfurization rate (95.76 %) after seven cycles. The catalytic reaction mechanism involving peroxide state and electronic synergy was elucidated by experiments and analyses (XPS, EPR, etc.). This catalytic structure provides a new perspective for the research on supported catalysts. Download: Download high-res image (151KB) Download: Download full-size image