In Situ Implanting ZrW2 O7 (OH)2 (H2 O)2 Nanorods into Hierarchical Functionalized Metal-Organic Framework via Solvent-Free Approach for Upgrading Catalytic Performance.

Abstract

Host-guest catalyst provides new opportunities for targeted applications and the development of new strategies for preparing host-guest catalysts is highly desired. Herein, an in situ solvent-free approach is developed for implanting ZrW2 O7 (OH)2 (H2 O)2 nanorods (ZrW-NR) in nitro-functionalized UiO-66(Zr) (UiO-66(Zr)-NO2 ) with hierarchical porosity, and the encapsulation of ZrW-NR enables the as-prepared host-guest catalyst remarkably enhanced catalytic performance for both for oxidative desulfurization (ODS) and acetalization reactions. ZrW-NR@UiO-66(Zr)-NO2 can eliminate 500ppm sulfur within 9min at 40°C in ODS, and can transform 5.6mmol benzaldehyde after 3min at room temperature in acetalization reaction. Its turnover frequencies reach 72.3h-1 at 40°C for ODS which is 33.4 times higher than UiO-66(Zr)-NO2 , and 28140h-1 for acetalization which is the highest among previous reports. Density functional theory calculation result indicates that the W sites in ZrW-NR can decompose H2 O2 to WVI -peroxo intermediates that contribute to catalytic activity for the ODS reaction. This work opens a new solvent-free approach for preparing MOFs-based host-guest catalysts to upgrade their redox and acid performance.