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Commercialization of Zn‐metal anodes with low cost and high theoretical capacity is hindered by the poor reversibility caused by dendrites growth, side reactions, and the slow Zn2+‐transport and reaction kinetics. Herein, a reversible heterogeneous electrode of Zn‐nanocrystallites/polyvinyl‐phosphonic acrylamide (Zn/PPAm) with fast electrochemical kinetics is designed for the first time: phosphonic acid groups with strong polarity and chelation effect ensure structural reversibility and stability of the three‐dimensional Zn‐storage‐host PPAm network and the Zn/PPAm hybrid; hydrophobic carbon chains suppress side reactions such as hydrogen evolution and corrosion; weak electron‐donating amide groups constitute Zn2+‐transport channels and promote “desolvation” and “solvation” effects of Zn2+ by dragging the PPAm network on the Zn‐metal surface to compress/stretch during Zn plating/stripping, respectively; and the heterostructure and Zn nanocrystallites suppress dendrite growth and enhance electrochemical reactivity, respectively. Thus, the Zn/PPAm electrode shows cycle reversibility of over 6000 h with a hysteresis voltage as low as 31 mV in symmetrical cells and excellent durability and flexibility in fiber‐shaped batteries. A reversible Zn nanocrystallites/polyvinyl‐phosphonic acrylamide (Zn/PPAm) heterozygote electrode with fast kinetics is designed. The heterostructure Zn/PPAm electrode comprising Zn nanocrystallites with the PPAm polymer suppresses dendrite growth and enhances the electrochemical activity of the Zn anode. Meanwhile, the carbon chains of the polymer can suppress side reactions and amide groups have Zn2+‐transport channels to promote the “desolvation” and “solvation” effects of Zn ions during the charging/discharging process.

A critical step toward the rational design of new catalysts that achieve selective and efficient reduction of CO₂ to specific hydrocarbons and oxygenates is to determine the detailed reaction mechanism including kinetics and product selectivity as a function of pH and applied potential for known systems. To accomplish this, we apply ab initio molecular metadynamics simulations (AIMμD) for the water/Cu(100) system with five layers of the explicit solvent under a potential of −0.59 V [reversible hydrogen electrode (RHE)] at pH 7 and compare with experiment. From these free-energy calculations, we determined the kinetics and pathways for major products (ethylene and methane) and minor products (ethanol, glyoxal, glycolaldehyde, ethylene glycol, acetaldehyde, ethane, and methanol). For an applied potential (U) greater than −0.6 V (RHE) ethylene, the major product, is produced via the Eley–Rideal (ER) mechanism using H₂O + e⁻. The rate-determining step (RDS) is C–C coupling of two CO, with ΔG ‡ = 0.69 eV. For an applied potential less than −0.60 V (RHE), the rate of ethylene formation decreases, mainly due to the loss of CO surface sites, which are replaced by H*. The reappearance of C₂H₄ along with CH₄ at U less than −0.85 V arises from *CHO formation produced via an ER process of H* with nonadsorbed CO (a unique result). This *CHO is the common intermediate for the formation of both CH₄ and C₂H₄. These results suggest that, to obtain hydrocarbon products selectively and efficiency at pH 7, we need to increase the CO concentration by changing the solvent or alloying the surface.

After a century of history of cathodic protection (CP) of iron and steel, this paper critically reviews the state of the art in the science and engineering and assesses the fitness of CP as an effective technology to tackle the challenges related to infrastructure corrosion. This paper focuses on CP of iron-based alloys embedded in porous media, such as soil or concrete, as these two major applications of CP technology share many similarities. First, the scientific understanding of CP is reviewed and different competing theories are discussed. There is wide agreement that corrosion protection of steel is achieved thanks to a combination of immediate activation polarization and the beneficial changes in electrolyte chemistry that are gradually occurring at the steel surface when a protection current is flowing toward a steel electrode. A major and well-documented technological advantage of these “chemical effects” is that the protective effect of CP is maintained during temporal loss of protection current, e.g., due to survey work related shut-offs or anodic interference. However, the relationships between these chemical concentration changes in the porous medium and the protection current are complex, and, as this review shows, cannot reliably be described with state-of-the-art approaches. Moreover, in this paper, different hypotheses for the mechanism of corrosion protection in heterogeneous situations (galvanic elements), as they are generally occurring in practice, are discussed. It is revealed that understanding the working mechanism of CP in heterogeneous conditions remains a critical scientific challenge. The longstanding debate concerns the question whether CP results mainly in a reduction of number and size of actively corroding areas, or in a reduction of the corrosion rate at the actively corroding sites. Additionally, the literature addressing the interrelation between microbiologically influenced corrosion and CP is here reviewed, and recent progress as well as limitations of the existing literature are highlighted. In a second part, engineering practice and CP protection criteria are reviewed. It is found that the approaches stipulated in international standard are unreliable. This can be traced back to the assessment criteria being empirical and incapable of adequately taking into account the complexity of the underlying processes. Finally, recommendations for future developments are made. Particular opportunities are seen in embracing the progress made in numerical modeling, such as reactive transport modeling in porous media, and considering the interdependence between the involved processes, namely the interdependence between transport processes, chemical reactions, and electrode kinetics.

Electrochemical reduction of N 2 to NH 3 provides an alternative to the Haber−Bosch process for sustainable, distributed production of NH 3 when powered by renewable electricity. However, the development of such process has been impeded by the lack of efficient electrocatalysts for N 2 reduction. Here we report efficient electroreduction of N 2 to NH 3 on palladium nanoparticles in phosphate buffer solution under ambient conditions, which exhibits high activity and selectivity with an NH 3 yield rate of ~4.5 μg mg −1 Pd h −1 and a Faradaic efficiency of 8.2% at 0.1 V vs. the reversible hydrogen electrode (corresponding to a low overpotential of 56 mV), outperforming other catalysts including gold and platinum. Density functional theory calculations suggest that the unique activity of palladium originates from its balanced hydrogen evolution activity and the Grotthuss-like hydride transfer mechanism on α-palladium hydride that lowers the free energy barrier of N 2 hydrogenation to *N 2 H, the rate-limiting step for NH 3 electrosynthesis. The Haber-Bosch process, producing NH 3 from N 2 , is a crucial yet energetically demanding reaction, inspiring interest in the exploration of ambient-condition alternatives. Here, authors develop a palladium electrocatalyst that shows a high selectivity and activity for N 2 reduction to NH 3 .

A recently introduced methodology (Sci Rep 14:17314) for estimating the implicit anodic and cathodic current components of a net, experimentally measured current at a given potential is applied to surface-confined, diffusionless electrode processes. Under the simplest conditions of a voltammetric experiment with a linear potential sweep, the conventional voltammogram is deconstructed into genuine anodic and cathodic current components. These components exhibit high sensitivity to electrode kinetics, offering an alternative perspective on electrochemical reversibility compared to conventional cyclic voltammetry. To calculate the implicit current components, prior knowledge of the formal potential of the redox couple is required, along with integration of the net current. Once determined, these current components allow independent estimation of the electrode kinetic parameters, i.e., standard rate constant and the electron transfer coefficient, either through Tafel-like analysis or by employing a novel form of differential current. In the kinetic regime of very fast, seemingly electrochemically reversible electrode reactions—where the net current becomes independent of electrode kinetics—the implicit current components remain highly sensitive to these kinetics. The theoretical considerations are supported by experiments on the reduction of methylene blue, covalently immobilized on a gold electrode via the self-assembly of a mixed peptide-thiol layer.

Chemical kinetics can be a useful tool for determining the optimal operating time of electrochemical processes. The main objective of the study was to determine the mineral oil removal rate by sono-electrochemical treatment. In this study, zero-, first-, and second-order kinetic models were used to determine the reaction rate of mineral oil removal with the sono-electrochemical process. The reaction rate experiments were conducted under the following optimal conditions: 8 min of treatment time, a current density of 53.1 A/m2, and a flow rate of 0.23 L/s. It was found that the changes in mineral oil concentrations follow second-order kinetics with a coefficient of determination of 0.9732. The mineral oil removal efficiency was 94.4%. This study concludes that sono-electrochemical process could be a promising technology for the removal of mineral oil from wastewater, and that the mineral oil removal rate can be determined by chemical kinetics. The results obtained may be useful for the optimization of the sono-EC process and reactor design.

The integrated electrocoagulation-assisted adsorption (ECA) system with a solar photovoltaic power supply has gained more attention as an effective approach for reduction chemical oxygen demand (COD) from pharmaceutical wastewater (PhWW). In this research, the ECA system was used for the treatment of PhWW. Several operating parameters were investigated, including electrode number, configuration, distance, operating time, current density, adsorption time, and temperature. A current density of 6.656 mA/cm 2 , six electrodes, a 20-min time, a 4 cm distance, an MP-P configuration, and a 45 °C temperature produced the maximum COD reductions, where the operating cost of conventional energy was 0.273 $/m 3 . The EC, adsorption, and combination of EC and adsorption processes achieved efficient COD reductions of 85.4, 69.1, and 95.5%, respectively. The pseudo-second-order kinetic model and the Freundlich isotherm fit the data of the endothermic adsorption process. Therefore, it was found that the combination processes were superior to the use of these processes in isolation to remove COD. Graphical abstract

To non‐destructively resolve and diagnose the degradation mechanisms of lithium‐ion batteries (LIBs), it is necessary to cross‐scale decouple complex kinetic processes through the distribution of relaxation times (DRT). However, LIBs with low interfacial impedance render DRT unreliable without data processing and closed‐loop validation. This study proposes a hierarchical analytical framework to enhance timescale resolution and reduce uncertainty, including interfacial impedance reconstruction and multi‐dimensional DRT analysis. Interfacial impedance is reconstructed by eliminating simulated inductive and diffusive impedance based on a high‐fidelity frequency‐domain model. Multi‐dimensional DRT decouples solid electrolyte interphase (SEI) and charge transfer (CT) processes by the reversibility of electrochemical reactions with state of charge (SOC) to characterize electrode kinetic evolution driven by SOC and temperature through timescales and peak area. The findings reveal that reconstructed impedance improves the accuracy of identified time constants by ≈20%. Cross‐scale DRT results reveal that SOCs below 10% at 25 °C effectively distinguish electrode kinetics due to the high correlation between cathodic CT and SOC. Kinetic metrics characterize that anodic SEI or CT are different control steps limiting the low‐temperature performance of different cells. This work underscores the potential of the proposed framework for non‐destructive diagnostics of kinetic evolution. Xue et al. propose a hierarchical framework for cross‐scale decoupling of complex kinetic processes with inductance and diffusion processes rooted in milliohm‐level interfacial impedance. This approach encompasses data pre‐processing, interfacial impedance reconstruction, and multi‐dimensional distribution of relaxation time (DRT) analysis, improving DRT accuracy by 20% and further illuminating the potential of DRT in cross‐scale nondestructive diagnosis.

The low energy density, unsatisfied cycling performance, potential safety issue and slow charging kinetics of the commercial lithium-ion batteries restrained their further application in the fields of fast charging and long-haul electric vehicles. Monoclinic TiNb2O7 (TNO) with the theoretical capacity of 387 mAh g−1 has been proposed as a high-capacity anode materials to replace Li4Ti5O12. In this work, homovalent doping strategy was used to enhance the electrochemical performance of TiNb2O7 (TNO) by employing Zr to partial substitute Ti through solvothermal method. The doping of Zr4+ ions can enlarge the lattice structure without changing the chemical valence of the original elements, refine and homogenize the grains, improve the electrical conductivity, and accelerate the ion diffusion kinetics, and finally enhance the cycle and rate performance. Specifically, Z0.05-TNO shows initial discharge capacity of as high as 312.2 mAh g−1 at 1 C and 244.8 mAh g−1 at 10 C, and still maintains a high specific capacity of 171.3 mAh g−1 after 800 cycles at 10 C. This study provides a new strategy for high-performance fast-charging energy storage electrodes. The doping of Zr4+ ions into TiNb2O7 can enlarge the lattice structure, refine and homogenize the grains, improve the electrical conductivity, and accelerate the ion diffusion kinetics, and finally enhance the cycle and rate performance. [Display omitted] •We synthesized Ti0·95Zr0·05Nb2O7 anode materials by solvothermal method.•The electronic conductivity of TiNb2O7 can be improved by Zr doping.•The lithium-ion conductivity of TiNb2O7 can be enhanced by Zr doping.•The Z0.05-TNO possesses superior cycle and rate performance.

Artificial photosynthesis and the production of solar fuels could be a key element in a future renewable energy economy providing a solution to the energy storage problem in solar energy conversion. We describe a hybrid strategy for solar water splitting based on a dye sensitized photoelectrosynthesis cell. It uses a derivatized, core–shell nanostructured photoanode with the core a high surface area conductive metal oxide film––indium tin oxide or antimony tin oxide––coated with a thin outer shell of TiO ₂ formed by atomic layer deposition. A “chromophore–catalyst assembly” 1, [(PO ₃H ₂) ₂bpy) ₂Ru(4-Mebpy-4-bimpy)Rub(tpy)(OH ₂)] ⁴⁺, which combines both light absorber and water oxidation catalyst in a single molecule, was attached to the TiO ₂ shell. Visible photolysis of the resulting core–shell assembly structure with a Pt cathode resulted in water splitting into hydrogen and oxygen with an absorbed photon conversion efficiency of 4.4% at peak photocurrent.