1. COF-supported zirconium oxyhydroxide as a versatile heterogeneous catalyst for Knoevenagel condensation and nerve agent hydrolysis
- Author
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Pragalbh Shekhar, Venkata Swaroopa Datta Devulapalli, Reshma Reji, Himan Dev Singh, Aleena Jose, Piyush Singh, Arun Torris, Chatakudath P. Vinod, John A. Tokarz, III, John J. Mahle, Gregory W. Peterson, Eric Borguet, and Ramanathan Vaidhyanathan
- Subjects
Interface science ,Nanoparticles ,Physical organic chemistry ,Science - Abstract
Summary: A composite of catalytic Lewis acidic zirconium oxyhydroxides (8 wt %) and a covalent organic framework (COF) was synthesized. X-ray diffraction and infrared (IR) spectroscopy reveal that COF’s structure is preserved after loading with zirconium oxyhydroxides. Electron microscopy confirms a homogeneous distribution of nano- to sub-micron-sized zirconium clusters in the COF. 3D X-ray tomography captures the micron-sized channels connecting the well-dispersed zirconium clusters on the COF. The crystalline ZrOx(OH)y@COF’s nanostructure was model-optimized via simulated annealing methods. Using 0.8 mol % of the catalyst yielded a turnover number of 100–120 and a turnover frequency of 160–360 h−1 for Knoevenagel condensation in aqueous medium. Additionally, 2.2 mol % of catalyst catalyzes the hydrolysis of dimethyl nitrophenyl phosphate, a simulant of nerve agent Soman, with a conversion rate of 37% in 180 min. The hydrolytic detoxification of the live agent Soman is also achieved. Our study unveils COF-stabilized ZrOx(OH)y as a new class of zirconium-based Lewis + Bronsted-acid catalysts.
- Published
- 2023
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