Ammonia electro-oxidation on nickel hydroxide: phases, pH and poisoning.

Nickel hydroxide is a leading alternative to platinum group metals for electrocatalysis of the ammonia oxidation reaction (AOR), an important process for energy conversion and environmental remediation. Nevertheless, the dependence of AOR electrocatalysis on the different crystalline phases at the electrode surface (α-Ni(OH)/γ-NiOOH β-Ni(OH)/β-NiOOH) has never been investigated. Herein, the crystalline β-Ni(OH) and the disordered α-Ni(OH) were synthesized and characterized by XRD, HRSEM, and Raman and FTIR spectroscopies.

Active Surfaces Formed in Liquid Crystal Polymer Networks.

There is an increasing interest in animating materials to develop dynamic surfaces. These dynamic surfaces can be utilized for advanced applications, including switchable wetting, friction, and lubrication. Dynamic surfaces can also improve existing technologies, for example, by integrating self-cleaning surfaces on solar cells.

An experimental approach for controlling confinement effects at catalyst interfaces.

Catalysts are conventionally designed with a focus on enthalpic effects, manipulating the Arrhenius activation energy. This approach ignores the possibility of designing materials to control the entropic factors that determine the pre-exponential factor. Here we investigate a new method of designing supported Pt catalysts with varying degrees of molecular confinement at the active site.

A Simple and Efficient Device and Method for Measuring the Kinetics of Gas-Producing Reactions.

We present a new device for quantifying gases or gas mixtures based on the simple principle of bubble counting. With this device, we can follow reaction kinetics down to volume step sizes of 8-12 μL. This enables the accurate determination of both time and size of these gas quanta, giving a very detailed kinetic analysis.

Highly efficient production of chiral amines in batch and continuous flow by immobilized ω-transaminases on controlled porosity glass metal-ion affinity carrier.

In this study, two stereocomplementary ω-transaminases from Arthrobacter sp. (AsR-ωTA) and Chromobacterium violaceum (Cv-ωTA) were immobilized via iron cation affinity binding onto polymer-coated controlled porosity glass beads (EziG). The immobilization procedure was studied with different types of carrier materials and immobilization buffers of varying compositions, concentrations, pHs and cofactor (PLP) concentrations.

Cooperative Surface-Particle Catalysis: The Role of the "Active Doughnut" in Catalytic Oxidation.

We consider the factors that govern the activity of bifunctional catalysts comprised of active particles supported on active surfaces. Such catalysts are interesting because the adsorption and diffusion steps, which are often discounted in "conventional" catalytic scenarios, play a key role here. We present an intuitive model, the so-called "active doughnut" concept, defining an active catalytic region around the supported particles.

Selective Catalytic Oxidation of Cyclohexene with Molecular Oxygen: Radical Versus Nonradical Pathways.

We study the allylic oxidation of cyclohexene with O under mild conditions in the presence of transition-metal catalysts. The catalysts comprise nanometric metal oxide particles supported on porous N-doped carbons (M/N:C, M=V, Cr, Fe, Co, Ni, Cu, Nb, Mo, W). Most of these metal oxides give only moderate conversions, and the majority of the products are over-oxidation products.

Boosting the Supercapacitance of Nitrogen-Doped Carbon by Tuning Surface Functionalities.

The specific capacitance of a highly porous, nitrogen-doped carbon is nearly tripled by orthogonal optimization of the microstructure and surface chemistry. First, the carbons' hierarchical pore structure and specific surface area were tweaked by controlling the temperature and sequence of the thermal treatments. The best process (pyrolysis at 900 °C, washing, and subsequent annealing at 1000 °C) yielded a carbon with a specific capacitance of 117 F g -nearly double that of a carbon made by a typical single-step synthesis at 700 °C.

Cooperative Catalysis for Selective Alcohol Oxidation with Molecular Oxygen.

The activation of dioxygen for selective oxidation of organic molecules is a major catalytic challenge. Inspired by the activity of nitrogen-doped carbons in electrocatalytic oxygen reduction, we combined such a carbon with metal-oxide catalysts to yield cooperative catalysts. These simple materials boost the catalytic oxidation of several alcohols, using molecular oxygen at atmospheric pressure and low temperature (80 °C).