Enhancing Electrocatalytic Hydrodechlorination through Interfacial Microenvironment Modulation

Abstract

Electrochemical reduction (ER) is a promising approach to safely remove pollutants. However, sluggish reaction kinetics and significant side reactions considerably limit the applicability of this green process. Herein, we uncovered the previously ignored role of interfacial hydrophilicity in determining the ER performance through electron microscopy observations, contact angle (CA) analysis, and electrochemical measurements. A Pd/C electrocatalyst forms dense nanopores on the electrode surface, rendering it highly hydrophobic and achieving a CA of up to 145°. This imposes a large mass-transfer barrier for the diffusion of water and pollutants into Pd sites. Moreover, the release of H 2 is suppressed, which changes the solid−liquid (Pd−polluted water) interface into a solid−gas (H 2 )−liquid interface. This further slows down mass transfer and the decontamination process. This dilemma can be easily alleviated by adding hydrophilic polymers like polyethylene glycol to increase hydrophilicity and improve mass transfer. By this way, the activity and Faraday efficiency of Pd/C in the electrochemical hydrodehalogenation of 2,4-dichlorophenol could be increased by 4−5 times. Moreover, this interfacial microenvironment modulation strategy is parallel to other approaches, such as Pd structural engineering, and therefore these strategies can be combined to further increase the electrochemical decontamination performance of electrocatalysts.

Insights into Electrochemical Dehalogenation by Non-Noble Metal Single-Atom Cobalt with High Efficiency and Low Energy Consumption

“…As illustrated in Figure S26, three peaks were observed in the potential range of −1.2 to −1.0 V, −0.85 to −0.75 V, and −0.4 to 0.3 V, corresponding to H 2 , H* abs (H* absorbed in the catalyst lattice), and H* ads (H* adsorbed on the catalyst surface), respectively. , As shown in Figure S27, the Tafel slopes of Co–N/C and N/C were 141 and 116 mV dec –1 , respectively. Compared with N/C, Co–N/C showed an increase in the Tafel slope, demonstrating the HER-suppressing activity of Co–N/C . Co–N/C enhanced the dissociation of water and promoted the generation of H*.…”

Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model

“…Here we have considered only one of the HFOs known to produce CF 3 CHO, 10,11 and by extension, HFC-23; however, emissions of other CF 3 CHO-producing HFOs are also projected to grow substantially in the coming decades. 34 Our results imply a potential need to reconsider the labelling of HFOs as "low-GWP" alternatives, with more precise quantication of the HFC-23 quantum yield from CF 3 CHO critical for understanding the true climate impact of HFO use.…”

Rational Design and Structural Regulation of Robust Catalysts for Electrocatalytic Hydrodechlorination: From Nanostructures to Single Atoms

“…Liu et al conducted surface-enhanced Raman spectroscopy and found that H ads * is the primary active species in EHDC . Additionally, the H* contribution could be determined by analyzing the electron spin resonance characteristic peaks ( e.g., nine characteristic peaks) or by scavenger for H* radicals. , Lou et al used tert -butanol as an H* scavenger to remove H* from EHDC and quantified the contribution of H* …”