Enhancing the Catalysis of Oxygen Reduction Reaction via Tuning Interfacial Hydrogen Bonds

Abstract Proton activity at the electrified interface is central to the kinetics of proton-coupled electron transfer (PCET) reactions for making chemicals and fuels. Here we employed a library of protic ionic liquids in an interfacial layer on Pt and Au to alter local proton activity, where the intrinsic ORR activity was enhanced up to 5 times, exhibiting a volcano-shaped dependence on the pKa of the ionic liquid. The enhanced ORR activity was attributed to favorable proton transfer kinetics for strengthened hydrogen bonds between the ionic liquid to the ORR product with comparable pKa. This proposed mechanism was supported by in situ surface-enhanced Fourier-Transform Infrared Spectroscopy and our simulation of PCET kinetics based on computed proton vibrational wavefunction at the H-bond interface. These findings highlight opportunities in using non-covalent interactions of hydrogen bond structures and solvation environments at the electrified interface to tune the kinetics of ORR and beyond.

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Highly accelerated crystallization kinetics of poly(ethylene oxide)/ionic liquid mixtures by phase separation: The coupling effect of hydrogen bonds breaking

Polymer ◽

10.1016/j.polymer.2019.03.026 ◽

2019 ◽

Vol 171 ◽

pp. 70-79 ◽

Cited By ~ 2

Author(s):

Yunlei Chen ◽

Huan Luo ◽

Zhilin Xiao ◽

Yanhua Niu ◽

Guangxian Li

Keyword(s):

Ionic Liquid ◽

Phase Separation ◽

Hydrogen Bonds ◽

Ethylene Oxide ◽

Crystallization Kinetics ◽

Coupling Effect ◽

Liquid Mixtures ◽

Poly Ethylene Oxide ◽

Poly Ethylene ◽

Kinetics Of

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In-situ stabilization of silver nanoparticles in polymer hydrogels for enhanced catalytic reduction of macro and micro pollutants

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2020-1721 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Luqman Ali Shah ◽

Rida Javed ◽

Mohammad Siddiq ◽

Iram BiBi ◽

Ishrat Jamil ◽

...

Keyword(s):

Catalytic Reduction ◽

Thermo Gravimetric Analysis ◽

Activation Parameters ◽

Reduction Reaction ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

In Situ Stabilization ◽

Hybrid Hydrogels ◽

Kinetics Of

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.

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Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper

Nature Communications ◽

10.1038/s41467-021-23582-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jing Li ◽

Xiaoxia Chang ◽

Haochen Zhang ◽

Arnav S. Malkani ◽

Mu-jeng Cheng ◽

...

Keyword(s):

Mass Transport ◽

Active Sites ◽

Gas Diffusion ◽

Reduction Reaction ◽

Adsorbed Hydrogen ◽

Diffusion Type ◽

Proton Coupled Electron Transfer ◽

Alkaline Electrolytes ◽

Reaction Orders

AbstractRigorous electrokinetic results are key to understanding the reaction mechanisms in the electrochemical CO reduction reaction (CORR), however, most reported results are compromised by the CO mass transport limitation. In this work, we determined mass transport-free CORR kinetics by employing a gas-diffusion type electrode and identified dependence of catalyst surface speciation on the electrolyte pH using in-situ surface enhanced vibrational spectroscopies. Based on the measured Tafel slopes and reaction orders, we demonstrate that the formation rates of C2+ products are most likely limited by the dimerization of CO adsorbate. CH4 production is limited by the CO hydrogenation step via a proton coupled electron transfer and a chemical hydrogenation step of CO by adsorbed hydrogen atom in weakly (7 < pH < 11) and strongly (pH > 11) alkaline electrolytes, respectively. Further, CH4 and C2+ products are likely formed on distinct types of active sites.

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