Boosting Catalytic Performance of MOF-808(Zr) by Direct Generation of Rich Defective Zr Nodes via a Solvent-Free Approach

Abstract

Creation of rich open metal sites (defect) on the nodes of metal−organic frameworks (MOFs) is an efficient approach to enhance their catalytic performance in heterogeneous reactions; however, direct generation of such defects remains challenging. In this contribution, we developed an in situ green route for rapid fabrication of defective MOF-808(Zr) with rich Zr-OH/OH 2 sites (occupying 25% Zr coordination sites) and hierarchical porosity without the assistance of formic acid and solvent. The optimal MOF-808(Zr) not only displayed superior activity in oxidative desulfurization (ODS) for removing 1000 ppm sulfur at ambient temperature within 20 min but also could convert 3.8 mmol of benzaldehyde to (dimethoxymethyl)benzene within 90 s at 30 °C. The turnover frequencies reached 45.4 h −1 for ODS and 3451 h −1 for acetalization, outperforming the most reported MOFbased catalysts. Theoretical calculation and experimental results show that the formed Zr-OH/OH 2 can react with H 2 O 2 to generate peroxo-zirconium species, which readily oxidize the sulfur compound. Our work provides a new approach to the synthesis of defectrich MOF-808(Zr) with the accessibility of active sites for target reactions.

Atomically Dispersed Isolated Fe–Ce Dual-Metal-Site Catalysts for Proton-Exchange Membrane Fuel Cells

“… The results showed that the catalysts with different morphologies and Ce content showed similar carbon structures. Studies have shown that the presence of both defective carbon and graphitized carbon plays a significant role in improving electrochemical performance by fine-tuning the local electronic and geometric characteristics in the carbon matrix . Additionally, the FeCe-SAD/HPNC catalyst was in a moderate-intensity graphitization, which was conducive to improving the catalytic performance of the ORR.…”

Boosting Catalytic Oxidative Desulfurization Performance over Yolk–Shell Nickel Molybdate Fabricated by Defect Engineering

“…However, when DMSO is added, the desulfurization efficiency is completely inhibited. Therefore, it can be inferred that · OH radicals might be the major active intermediates during the ODS reaction . In order to prove this assumption, ESR spectroscopy with the existence of the radical trapping reagent 5,5-dimethyl-1-pyrroline- N -oxide (DMPO) was conducted (Figure b) .…”

“…Therefore, it can be inferred that • OH radicals might be the major active intermediates during the ODS reaction. 63 In order to prove this assumption, ESR spectroscopy with the existence of the radical trapping reagent 5,5-dimethyl-1pyrroline-N-oxide (DMPO) was conducted (Figure 6b). 64 It is worth noticing that no free radical signal is detected without YS-V O -NMO, while a strong fourfold peak signal belonging to DMPO− • OH is observed after 1 h of reaction with the presence of the catalyst.…”

Amorphization Boost Multi‐Ions Storage for High‐Performance Aqueous Batteries

“…[18][19][20] The random long-range networks in the amorphous phase provide ample isotropic ion diffusion routes and large numbers of active sites (defects/vacancies) that enhance the ion-intercalation pseudocapacitance of the material. [16] Furthermore, the loose structure of amorphous materials usually accommodates small lattice distortion and volume expansion during cation insertion/extraction, which enhances the cycling stability. [19,21] Unfortunately, to our knowledge, amorphization engineering for multi-ion storage has not been reported.…”