• Energy Research

Summary Simulated curves compared to recorded data have provided a breadth of insight into mechanisms and kinetic aspects of charge transfer at the liquid|liquid interface (LLI). This is often performed with software employing finite element methods (FEMs). The advent and application of this asset to soft interfacial chemistry has allowed a more facile exploration of geometric considerations, the role of interfacial size (from macro to nano), while simultaneously expanding to include homo/heterogeneous reactions such as electrocatalytic, photochemical, nanoparticle interactions, etc. This article provides insight into the status of the field of LLI FEM studies as well as a perspective as to what role simulations and numerical analysis will play in the future.

AbstractThe water oxidation process in acidified water/acetonitrile mixtures was studied by cyclic voltammetry using fluorinated tin oxide (FTO) electrodes modified layer‐by‐layer with deposited bilayers of positively charged poly(diallyldimethylammonium chloride) (PDDA) polymer and negatively charged citrate‐stabilized iridium oxide (IrO2) nanoparticles. The voltammetric profiles obtained at high water contents resemble those in aqueous media and remain approximately unchanged. However, as the water content decreases below a water mole fraction (XH2O) of 0.6, a tipping point is reached and the onset potential for water oxidation gradually decreases. This reflects an enhanced reactivity, and therefore lower overpotential, of water molecules towards oxidation in water/acetonitrile mixtures. These lower kinetic barriers towards water oxidation are rationalized based on the degradation of the hydrogen bond network upon the formation of water/acetonitrile mixtures. Thus, as the ice‐like structure of neat water transitions to clusters and low‐bonded oligomers, these water molecules in more “free” states exhibit an enhanced susceptibility to water oxidation.

Electrocatalysis at the interface between two immiscible elec?trolyte solutions (ITIES) is an emerging field of research, which allows the separation of reactants according to their lipophilicity. Electrocatalysts of various natures (noble metals, carbon-based and inorganic nanomaterials, enzymes, and supramolecular ensembles) are assembled at the ITIES, either spontaneously or following the application of an interfacial Galvani potential difference. While primarily used for the electrocatalysis of the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER), recent work has focused on the electrocatalysis of the oxygen evolution reaction (OER) and the electrocatalytic oxidation of elemental sulfur (S8) and an organosulfur compound. Protocols to compare electrocatalytic performances at the ITIES call for careful data analysis and a detailed knowledge of the catalyst’s morphological parameters (e.g., active surface area and catalyst loading). However, standardisation of such protocols at the ITIES has yet to be implemented and is required to allow better comparison of the results from individual biphasic systems.

Abstract Given the ever-growing awareness on global warming, much interest has focused on new and effective ways to manage energy, especially by harvesting and exploiting low-temperature heat sources, ubiquitous in the modern environment. Here, the holy grail is the direct conversion of heat into electricity especially using thermoelectric devices, and in this contribution, we focus on thermoelectrochemical systems. We give a brief overview of the most common thermally regenerative electrochemical cells developed nowadays with a short overview of their thermodynamic derivation, and we collect some of the most recent results in terms of their thermoelectrochemical properties, in particular, their temperature coefficients. We see that although the most used redox couples are based on Fe3+/Fe2+ and their derivates, thermodiffusion effects and other entropy-related phenomena are attracting the attention of the scientific community and boosting astonishing results. On the other hand, thermally regenerative batteries are emerging, showing modest performance.

The safe recycling of spent LIBs is challenging, as they often contain residual energy. Left untreated, this can trigger a thermal runaway and result in disaster during the recycling process. Electrochemical discharge method is an easy and inexpensive method to eliminate this hazard.

Electrolyte stability is governed by its oxidation and reduction potentials, not by the energy levels of its HOMO and LUMO.

The formation and the dissociation of metal hydrides are key steps within the hydrogen evolution reaction (HER) pathway for photochemical water splitting, but also impacts a wide range of other catalytic, industrial, and biochemical reactions. Herein, we describe our recent work studying HER at the interface between two immiscible electrolyte solutions (ITIES), between water|1,2-dichloroethane. This is a unique platform for evaluating the kinetics/thermodynamics for metallocene hydride formation using decamethylruthenocene. In this approach, an aqueous acid serves as the proton source and is pumped across the ITIES via an externally applied potential or the use of a phase transfer catalyst. Simulated curves developed using COMSOL Multiphysics software and compared to experimental ones, indicate a modified EC′ (electrochemical–chemical) mechanism for the decamethylruthenocene hydride formation. In the proposed pathway, decamethylruthenocene hydride is metastable in 1,2-dichloroethane and persists on the ti...