The oxygen evolution reaction (OER) is a key process for renewable energy storage. However, developing non-noble metal OER electrocatalysts with high activity, long durability and scalability remains major challenge. Herein, activity stability in alkaline solution were discovered mixed nickel/cobalt hydroxide electrocatalysts, which derived one-step procedure from oriented surface-mounted metal-organic framework (SURMOF) thin films that had been directly grown layer-by-layer on macro-...

Abstract Fundamental understanding of the influence so‐called spectator electrolyte species on catalytic activity electrodes is considered as a relatively novel direction in electrocatalysis. Numerous recent examples show that seemingly inert components drastically performance centers. Even alkali metal cations aqueous electrolytes at high pH values can change reaction turnover frequency by orders magnitude, depending their nature, from Li + to Cs . Here, we use several electrodes, namely...

Metal-organic frameworks (MOFs) and their derivatives are considered as promising catalysts for the oxygen reduction reaction (ORR) evolution (OER), which important many energy provision technologies, such electrolyzers, fuel cells some types of advanced batteries. In this work, a "strain modulation" approach has been applied through use surface-mounted NiFe-MOFs in order to design an bifunctional ORR/OER electrocatalyst. The material exhibits excellent OER activity alkaline media, reaching...

Metal oxides are important functional materials with a wide range of applications, especially in the field electrocatalysis. However, quick and accurate assessment their real electroactive surface area (ECSA), which is paramount importance for evaluation performance, remains challenging task. Herein, we present relatively simple strategy an situ determination ECSA commonly used metal oxide catalysts, namely Ni-, Co-, Fe-, Pt-, Ir-based oxides. Similar to well-established practice...

Understanding the properties of electrical double layer (EDL) is one interdisciplinary topics that plays a key role in investigation numerous natural and artificial systems. We present experimental evidence about influence nature alkali metal cations on EDL capacitance for two model electrodes, Pt(111) Au(111), 0.05 M AMClO4 ( AM: Li+, Na+, K+, Rb+, Cs+) electrolytes using impedance spectroscopy measurements. Our data show counterintuitively differential both electrodes measured close to...

Abstract Herein, we demonstrate an easy way to improve the hydrogen evolution reaction (HER) activity of Pt electrodes in alkaline media by introducing Ni–Fe clusters. As a result, overpotential needed achieve current density 10 mA cm −2 H 2 ‐saturated 0.1 m KOH is reduced for model single‐crystal down about 70 mV. To our knowledge, these modified outperform any other reported electrocatalysts tested under similar conditions. Moreover, influence 1) Ni Fe ratio, 2) cluster coverage, and 3)...

Abstract Materials derived from surface‐mounted metal–organic frameworks (SURMOFs) are promising electrocatalysts for the oxygen evolution reaction (OER). A series of mixed‐metal, heterostructured SURMOFs is fabricated by facile layer‐by‐layer deposition method. The obtained materials reveal record‐high electrocatalyst mass activities ≈2.90 kA g −1 at an overpotential 300 mV in 0.1 m KOH, superior to benchmarking precious and nonprecious metal electrocatalysts. This property assigned...

To optimize the performance of catalytic materials, it is paramount to elucidate dependence chemical reactivity on atomic arrangement catalyst surface.

The oxygen reduction reaction (ORR) is of great interest for future sustainable energy conversion and storage, especially concerning fuel cell applications. preparation active, affordable, scalable electrocatalysts their application in engines hydrogen cars a prominent step toward the air pollution, urban areas. Alloying nanostructured Pt with lanthanides promising approach to enhance its catalytic ORR activity, whereby development simple synthetic route turned out be nontrivial endeavor....

Abstract Quick and accurate determination of the real electroactive surface area oxide electrodes remains one most challenging but at same time important unsolved methodological tasks in field electroanalysis. For instance, widely used Brunauer−Emmett−Teller (BET) method unfortunately provides no direct connection to it. On other hand, its assessment through double layer capacitance is complicated not enough, as bulk films themselves contribute measured capacitance, mentioning frequency...

Results from Pt model catalyst surfaces have demonstrated that surface defects, in particular concavities, can improve the oxygen reduction reaction (ORR) kinetics. It is, however, a challenging task to synthesize nanostructured catalysts with such defective surfaces. Hence, we present one-step and upscalable top-down approach produce Pt/C (with ∼3 nm nanoparticle diameter). Using high-resolution transmission electron microscopy tomography, electrochemical techniques, high-energy X-ray...

The hydrogen evolution reaction (HER) is one of the two processes in electrolytic water splitting. Known for more than centuries, HER still receives great attention fundamental and applied science view its apparent simplicity (only electrons are transferred), fast kinetics acidic media, promising technological applications electrolyzers. However, exact nature active catalytic sites this often uncertain, especially at nonuniform metal electrodes. Identification such centers important, as will...

The hydrogen evolution reaction (HER) is of paramount importance for both fundamental and applied electrocatalysis. However, many issues related to understanding this remain unclear. These, instance, include a surprising pH dependence the electrode activities non-Tafel dependency HER-associated current various electrocatalysts. Even dominating mechanism at different potentials often difficult reveal. In article, we use electrochemical impedance spectroscopy estimate relative contribution...

Abstract A deeper understanding of electrified solid/liquid interfaces polycrystalline materials is crucial for optimizing energy conversion and storage devices, such as fuel cells, electrolyzers, supercapacitors. After more than a century research, the double‐layer capacitance (C DL ) has proven to be one few relatively easily experimentally accessible quantitative measures characterizing interfaces. However, despite their great importance, systematic C measurements are still not frequently...

Abstract The structure–activity relationship is a cornerstone topic in catalysis, which lays the foundation for design and functionalization of catalytic materials. Of particular interest catalysis hydrogen evolution reaction (HER) by palladium (Pd), envisioned to play major role realizing hydrogen‐based economy. Interestingly, experimentalists observed excess heat generation such systems, became known as debated “cold fusion” phenomenon. Despite considerable attention on this report, more...

The effects of seemingly inert alkali metal (AM) cations on the electrocatalytic activity electrode materials towards reactions essential for energy provision have become emphasis substantial research efforts in recent years. hydrogen and oxygen evolution during alkaline water electrolysis electro-reduction taking place fuel cells are particular importance. There is no universal theory explaining all details AM cation effect electrocatalysis. For example, it remains unclear how "spectator"...

Abstract Polymer membrane electrolyzers benefit from high‐pressure operation conditions and low gas cross‐over can either conduct protons (H + ) or hydroxide ions (OH − ). Both types of have a similar design, but differ in power density the choice catalysts. Despite significant endeavor their optimization, to date, there is no well‐established impedance model for detailed analysis type these devices. This complicates in‐situ characterization electrolyzers, hindering investigation degradation...

Nanostructured palladium (Pd) is a universal catalyst that widely used in applications ranging from catalytic converters of combustion engine cars to hydrogenation catalysts industrial processes. Standard protocols for synthesizing such nanoparticles (NPs) typically use bottom‐up approaches. They utilize special and often expensive physical techniques or wet‐chemical methods requiring organic surfactants. These surfactants should be removed before applications. In this article, the synthesis...

Abstract Taking cognizance of the United Nations Sustainable Development Goal 7 “affordable and clean energy” , metal–organic frameworks (MOFs) derived materials have spurred research interest in electrocatalysis. New findings made headway water splitting (oxygen evolution reaction hydrogen reaction) other electrocatalysis, including oxygen reduction electrochemical CO 2 reduction. Thanks to their structural versatility compositional modularity, MOFs offer bespoke design paradigms for...

Electrocatalysis for the oxygen evolution reaction (OER) is of great interest improving effectiveness water splitting devices. Decreasing anodic overpotential and simultaneously changing selectively to produce valuable chemicals instead O2 would be a major improvement overall cost efficiency. Some amines, when present in aqueous electrolytes, were recently shown change selectivity process generate H2 rather than on MnOx at pH 10. This results unusually high apparent "anodic activities". In...

Abstract Metal–organic frameworks (MOFs) and their derivatives are considered as promising catalysts for the oxygen reduction reaction (ORR) evolution (OER), which important many energy provision technologies, such electrolyzers, fuel cells some types of advanced batteries. In this work, a “strain modulation” approach has been applied through use surface‐mounted NiFe‐MOFs in order to design an bifunctional ORR/OER electrocatalyst. The material exhibits excellent OER activity alkaline media,...

Abstract In this work, we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes (in range from ~ 2 10 nm). Carbon supported nanoparticles narrow size distributions have been synthesized by applying an alternating voltage macroscopic bulk platinum structures, such as disks or wires. Without using any surfactants, shape particles can be changed adjusting parameters applied potential, frequency electrolyte...

Abstract Efficient electrocatalysis is most likely an answer to recent energy related challenges. Countless studies have been trying find the links between electrode/electrolyte interface structure, its composition, and resulting activity in order improve performance of numerous devices, such as electrolyzers, fuel cells, certain types batteries. However, this scientific field currently meets serious complications associated with prediction explanation unexpected influence seemingly inert...