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Electrochemical ammonia synthesis (EAS) presents an attractive alternative to the Haber–Bosch process due to the benefits of energy saving, low carbon emission, environmental friendliness, and so on. However, the competing hydrogen evolution reaction (HER) severely limits the yield, selectivity, and current efficiency of NH3. Although the accumulation and self‐aggregation of active hydrogen (H*) are the primary causes of the competing HER, it also serves as the critical active species and intermediate for the multistep hydrogenation and deoxygenation processes. Therefore, the sensible regulation of the H* generation and consumption are essential for enhancing EAS performance. And it is significant to thoroughly review the current strategies for H* control. Herein, a comprehensive introduction of H* to provide a fundamental understanding of its role in electrochemical reactions, including generation, conversion, identification, and quantification protocols is first proposed. In addition, the role and control strategies of H* in EAS are carefully summarized with a particular focus on regulating H* generation and consumption to enhance the activity, selectivity, and Faradaic efficiency. Finally, the remaining challenges and perspectives are discussed. This critical review is intended to offer a profound understanding of the regulation of H* in electrochemical reactions and the development of EAS technology. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are a crucial kind of pollutants in the environment due to their obvious features of severe toxicity, high volatility, and poor degradability. It is particularly urgent to control the emission of VOCs due to the persistent increase of concentration and the stringent regulations. In China, clear directions and requirements for reduction of VOCs have been given in the "national plan on environmental improvement for the 13th Five-Year Plan period". Therefore, the development of efficient technologies for removal and recovery of VOCs is of great significance. Recovery technologies are favored by researchers due to their advantages in both recycling VOCs and reducing carbon emissions. Among them, adsorption and membrane separation processes have been extensively studied due to their remarkable industrial prospects. This overview was to provide an up-to-date progress of adsorption and membrane separation for removal and recovery of VOCs. Firstly, adsorption and membrane separation were found to be the research hotspots through bibliometric analysis. Then, a comprehensive understanding of their mechanisms, factors, and current application statuses was discussed. Finally, the challenges and perspectives in this emerging field were briefly highlighted. [Display omitted]. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) have received widespread interest for their high atomic efficiency, enriched active sites, excellent catalytic performance, and low cost. However, the agglomeration of single metal atoms and the use of inactive additives for affixing powdery SACs on planar electrodes may reduce the density of active sites, diminish the charge transport to active sites, and thus suppress their performance. Herein, a series of metal–nitrogen–carbon single‐atom aerogels (M‐SAAs, M: Cu, Ni, Au, Ru) are synthesized via a universal strategy, in which the merits of metal organic frameworks and carbon aerogels are perfectly combined to prevent the agglomeration of single metal atoms and overcome the problem of poor electrical conductivity. The as‐prepared M‐SAAs can be directly employed as self‐supporting electrodes for the electrochemical dechlorination of 1,2‐dichloroethane, and outstanding activity and stability are observed. Significantly, the Cu‐SAA with abundant Cu−N4 sites shows an extraordinarily high ethylene production rate of 446 µmol h−1, with a selectivity of 99% and Faradaic efficiency of 64%. Moreover, theoretical calculations are performed to demonstrate the selectivity and activity of different metal active sites. This study provides a new strategy to exploit highly effective SACs and offers an intensive insight into the mechanism of electrochemical dechlorination reactions. [ABSTRACT FROM AUTHOR]

Carbon aerogels are a fascinating three‐dimensional (3D) monolithic porous material with remarkable physicochemical properties, including low density, large surface area, abundant pore structure, high electrical conductivity, chemical stability, environmental compatibility, adjustable surface chemistry, as well as controllable structural features. These properties endow carbon aerogels with excellent adsorption and catalytic performance. Therefore, they are widely applied in environmental chemistry for removing pollutants like oils, toxic organic solvents, dyes, heavy metal ions in aquatic environments, and volatile organic compounds (VOCs), carbon oxides (CO2, CO), nitrogen oxide (NOx), and hydrogen sulfide (H2S) in the atmosphere. In this paper, the preparation processes of carbon aerogels are fully reviewed, and their applications for environmental clean‐up based on adsorption and catalytic action are thoroughly addressed. In each section, the most recent representative studies will be highlighted. Finally, the challenges, outlooks, and prospects in this emerging and promising research field will be briefly discussed. [ABSTRACT FROM AUTHOR]

In this work, magnetic nanoparticles (MNPs) Fe 3 O 4 /CeO 2 synthesized by the method of impregnation oxidation-precipitation were used as the heterogeneous catalyst for the degradation of Pantoprazole. Response surface methodology based on central composite design was used to investigate the individual and the interactive effects of three process parameters on the Pantoprazole degradation, i.e. the initial pH of the solution, the dosage of H 2 O 2 and the initial concentration of Pantoprazole. Under the optimal conditions of pH 3.3, H 2 O 2 30.0 mM, Pantoprazole 20.0 mg L −1 , catalyst 2.0 g L −1 and 35 °C, the degradation percentage of Pantoprazole was 98.0% within 120 min. The obtained results agreed well with the modeling prediction ( R 2 = 0.9924, and Adj- R 2 = 0.9889), and the degradation reaction well followed the first-order kinetic with R 2 = 0.9986. According to the results of the iron leaching and the effects of the radical scavengers and the intermediates determination, a possible pathway of Pantoprazole degradation was proposed based on ·OH mechanism. [ABSTRACT FROM AUTHOR]

In this work, magnetic nanoparticles (MNPs) Fe 3 O 4 /CeO 2 were firstly synthesized using three different preparation methods, including coprecipitation, impregnation oxidation-precipitation and impregnation reduction-precipitation, respectively. The catalytic activities of Fe 3 O 4 /CeO 2 MNPs, prepared by above three methods, were compared systematically in terms of the degradation of orange G (OG). The impregnation oxidation-precipitation process was economical and maneuverable due to the usage of air, no need of nitrogen protection and higher utilization efficiency of iron. Response surface methodology based on central composite design were used to investigate the individual and interactive effects of three process parameters on the OG degradation, i.e. the initial pH of the solution, the dosage of H 2 O 2 and the initial concentration of OG. Under the optimal conditions of pH 2.5, H 2 O 2 30 mM, OG 50 mg L −1 , catalyst 2.0 g L −1 and 35 °C, the degradation percentage of OG was 98.2% within 120 min, which agreed well with the modeling prediction (R 2 = 0.9984, and Adj-R 2 = 0.9969). And the degradation reaction well followed the first-order kinetic with R 2 = 0.9969. The Fe 3 O 4 /CeO 2 -OX MNPs showed high catalytic activity, stability and reusability in the degradation of OG. [ABSTRACT FROM AUTHOR]

Oxygen functional groups on carbon materials could contribute to high performance for electrochemical dechlorination of 1,2-dichloroethane to ethylene. And the C atom neighbored to C=O at armchair edge is confirmed to be the main active site with the lowest energy barrier of 0.11 eV. [Display omitted] • A series of reduced graphene oxide with varying contents of oxygen functional groups have been successfully developed. • Oxygen functional groups were found to contribute to high performance for electrochemical DCEDR. • Correlation tests indicated that C=O was the main real active component for DCEDR to ethylene. • DFT calculations indicated that C atom neighbored to C=O at armchair edge was the active site for DCEDR. Carbon materials have been widely proved to be promising electrocatalysts for 1,2-dichloroethane (DCE) dechlorination reaction (DCEDR), while the significance or precise role of oxygen functional groups (OFGs) on the electrochemical reactivity has yet to be clarified. Herein, based on a sequence of reduced graphene oxide (RGOs) with varying contents of OFGs, we have found that the OFGs shown great effect on the electrochemical performance of carbon-based catalysts for DCEDR. Correlation tests indicated that the electrochemical DCEDR performance shown positive correlation only with the content of C=O, suggesting that C=O was the main real active component for DCEDR to ethylene. Further theoretical calculation results revealed that the C atom neighbored to C=O at armchair edge shown the lowest energy barrier of 0.11 eV for DCEDR, which was consistent with the result of experiment. Therefore, C atom neighbored to C=O at armchair edge was the real active site for DCEDR to ethylene. This work provides a deep understanding of the real nature of OFGs in electrocatalysis, and offers an efficient approach for rational exploitation of advanced carbon materials. [ABSTRACT FROM AUTHOR]

Achieving reversible plating/stripping of zinc (Zn) anodes is crucial in aqueous Zn‐ion batteries (AZIBs). However, undesired dendrite growth and parasitic side reactions severely deteriorate battery lifespan. The construction of stable protective coating is an effective strategy to enhance anode stability. In this study, a multifunctional nanodiamond (ND) inorganic layer is designed and constructed on both Zn and Cu electrodes that can both effectively inhibit dendrite growth and suppress Zn anode corrosion. Experimental results and theoretical calculations demonstrate that this artificial protective layer, with ultra‐high surface energy, enables the controlled creation of abundant nucleation sites (in the order of 1012 cm−2) for the homogenization of ion flux and electric field on the anode. It is found that zinc ions preferentially adhere to the diamond surfaces with lower diffusion barriers, leading to uniform zinc deposition. A symmetric cell with the ND‐protected Zn (Zn‐ND) anode exhibits reversible plating/stripping behavior for an impressive duration of over 3600 h at 1 mA cm−2. Furthermore, the MnO2||Zn full battery retains 90% of its initial capacity after 3500 cycles at 2 A g−1, and assembled hybrid capacitor operates smoothly over 65 000 cycles at 10 A g−1. These results underscore the potential of this coating as a promising solution for achieving highly stable Zn anodes for aqueous batteries. [ABSTRACT FROM AUTHOR]

Electrochemical hydrogen peroxide production from two-electron oxygen reduction reaction, a cost-effective, sustainable and reliable method compared with the traditional anthraquinone process, is attracting growing attention. However, it is challenged by the selectivity of electrocatalysts. In this context, nitrogen and oxygen co-doped ordered mesoporous carbon materials have been successfully fabricated. Benefiting from the ordered pore structure, better dispersion behavior and valid doping effect, a high selectivity (~95.00%), good activity and stability toward H 2 O 2 production were achieved. Systematic characterizations like physical adsorption, zeta potential, X-ray photoelectron spectroscopy and density functional theory (DFT) calculation revealed that interactive effects between pyridinic N and functional groups of COOH/C O C largely facilitated the desorption of intermediates (*OOH, * represents an unoccupied active site) in turn enhance the selectivity of electrocatalysts toward H 2 O 2 production. Interestingly, H 2 O 2 produced in situ was applied to Electro-Fenton, the formaldehyde mineralization rate was high to about 88.06%. These findings offer a rational chemical design of electrocatalysts toward H 2 O 2 production and pollutant purification. [ABSTRACT FROM AUTHOR]