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Hydrogen is one of the world's most important chemicals, with global production of about 50 billion kg/year. Currently, hydrogen is mainly produced from fossil fuels such as natural gas and coal, producing CO 2 . Water electrolysis is a promising technology for fossil-free, CO 2 -free hydrogen production. Proton exchange membrane (PEM)-based water electrolysis also eliminates the need for caustic electrolyte, and has been proven at megawatt scale. However, a major cost driver is the electrode, specifically the cost of electrocatalysts used to improve the reaction efficiency, which are applied at high loadings (>3 mg/cm 2 total platinum group metal (PGM) content). Core–shell catalysts have shown improved activity for hydrogen production, enabling reduced catalyst loadings, while reactive spray deposition techniques (RSDT) have been demonstrated to enable manufacture of catalyst layers more uniformly and with higher repeatability than existing techniques. Core–shell catalysts have also been fabricated with RSDT for fuel cell electrodes with good performance. Manufacturing and materials need to go hand in hand in order to successfully fabricate electrodes with ultra-low catalyst loadings (<0.5 mg/cm 2 total PGM content) without significant variation in performance. This paper describes the potential for these two technologies to work together to enable low cost PEM electrolysis systems. [ABSTRACT FROM AUTHOR]

The article presents research on electrochemical synthesis of ammonia with the focus on the study on alkaline exchange membrane (AEM)-based ammonia generation device by firm Proton OnSite, Lauren Greenlee of the National Institute of Standards and Technology (NIST) and Andrew Herring of Colorado School of Mines (CSM). It mentions the report of the U.S. Greenhouse Gas Inventory on emissions from ammonia production.

Recombinant proteins are promisingtools for tissue engineeringand drug delivery applications. Protein-based biomaterials have severaladvantages over natural and synthetic polymers, including precisecontrol over amino acid composition and molecular weight, modularswapping of functional domains, and tunable mechanical and physicalproperties. In this work, we describe recombinant proteins based onabductin, an elastomeric protein that is found in the inner hingeof bivalves and functions as a coil spring to keep shells open. Weillustrate, for the first time, the design, cloning, expression, andpurification of a recombinant protein based on consensus abductinsequences derived from Argopecten irradians. The molecular weight of the protein was confirmed by mass spectrometry,and the protein was 94% pure. Circular dichroism studies showed thatthe dominant structures of abductin-based proteins were polyprolineII helix structures in aqueous solution and type II β-turnsin trifluoroethanol. Dynamic light scattering studies illustratedthat the abductin-based proteins exhibit reversible upper criticalsolution temperature behavior and irreversible aggregation behaviorat high temperatures. A LIVE/DEAD assay revealed that human umbilicalvein endothelial cells had a viability of 98 ± 4% after beingcultured for two days on the abductin-based protein. Initial cellspreading on the abductin-based protein was similar to that on bovineserum albumin. These studies thus demonstrate the potential of abductin-basedproteins in tissue engineering and drug delivery applications dueto the cytocompatibility and its response to temperature. [ABSTRACT FROM AUTHOR]

Abstract: Resilin has emerged as a promising new biomaterial possessing attractive properties for tissue engineering applications. To date, proteins with repeating resilin motifs have been expressed with molecular weights less than 30kDa. This work describes the development of resilin-based proteins (repeating motif derived from Anopheles gambiae) 50kDa in size. A modular cloning scheme was utilized and features a recursive cloning technique that can seamlessly and precisely tune the number of resilin repeats. Previously-established resilin expression protocols (based on the Studier auto-induction method) were employed to express the proteins in Escherichia coli BL21(DE3)pLysS. Western blot and densitometry results demonstrated that only ∼50% of expressed proteins were the desired molecular weight. This finding suggested that either protein truncation or degradation occurred during protein expression. Preventing leaky expression, lowering the culture temperature, and harvesting during exponential phase resulted in up to 94% of the expressed proteins having the desired molecular weight. These expression conditions differ from previously-published resilin expression methods and are recommended when expressing proteins with a larger number of repetitive resilin sequences. [Copyright &y& Elsevier]

Surface-grafted elastin has found a wide range of uses such as sensing, tissue engineering and capture/release applications because of its ability to undergo stimuli-responsive phase transition. While various methods exist to control surface grafting in general, it is still difficult to control orientation as attachment occurs. This study investigates using an electric field as a new approach to control the surface-grafting of short elastin-like polypeptide (ELP). Characterization of ELP grafting to gold via quartz crystal microbalance with dissipation, atomic force microscopy and temperature ramping experiments revealed that the charge/hydrophobicity of the peptides, rearrangement kinetics and an applied electric field impacted the grafted morphology of ELP. Specifically, an ELP with a negative charge on the opposite end of the surface-binding moiety assembled in a more upright orientation, and a sufficient electric field pushed the charge away from the surface compared to when the same peptide was assembled in no electric field. In addition, this study demonstrated that assembling charged ELP in an applied electric field impacts transition behavior. Overall, this study reveals new strategies for achieving desirable and predictable surface properties of surface-bound ELP. [ABSTRACT FROM AUTHOR]

• Gold-immobilized ELPs were used to control the electron transfer of a redox probe. • Effective coverage was modeled as a function of ELP hydrophobicity and mass loading. • The model may be used in the future to design sensors and biomaterials. Elastin-like peptides (ELPs) immobilized to solid surfaces have recently gained attention for use in electrochemical applications in sensing as well as bioenabled electrode assembly. Key to the success of these applications is understanding how ELPs impact the access and electron transfer of reacting species to the solid surface (effective surface coverage). In this study, short ELPs with varying hydrophobicity and sequence length were designed for gold attachment, and the effect on the ability of a redox probe to access a gold surface was characterized by cyclic voltammetry. A quantitative model describing the relationship between ELP effective surface coverage as a function of mean hydrophobicity and mass loading was elucidated based on the results, showing the ability to precisely control surface properties by tuning the ELP sequence. This model will be useful for the design of surface-bound ELP sequences that exhibit desired effective surface coverage for electrochemical as well as biomaterial applications. [ABSTRACT FROM AUTHOR]

Cerium has a wide range of current and emerging applications, and the binding of cerium ions to solid substrates is important for cerium recovery, or in advanced material synthesis. In this study, we investigate the affinity of a surface‐bound peptide derived from the EF‐hand loop I of calmodulin for cerium (III) ions and compare the results to a scrambled control. Results obtained via quartz crystal microbalance with dissipation are used to estimate the dissociation constant between the bound EF‐hand loop I peptide and cerium (III) ions (1.3 ± 0.1 μM), which is comparable with other dissociation constants measured for EF‐hand peptides and cerium ions in solution reported this work and in literature (0.95‐5.8 μM). Circular dichroism also suggests that the peptide binds to cerium (III) ions in solution, and undergoes a secondary structural change upon binding. Overall, this study shows that EF‐hand loop peptides are capable of binding cerium (III) ions in solution and when attached to a solid substrate. [ABSTRACT FROM AUTHOR]

Interactions of a peptide with polyproline II helical secondary structure with maghemite (iron(III) oxide, Fe2O3) surfaces were characterized using a variety of surface techniques. A quartz crystal microbalance with dissipation was used to measure the hydrated mass and thickness (92 ± 29 ng/cm2 and 0.89 ± 0.27 nm, respectively) of a layer which formed after a sensor coated with Fe2O3 was exposed to the peptide in aqueous solution. The analysis revealed that the peptide formed a stable thin layer on the sensor. X‐ray photoelectron spectroscopy and Fourier‐transform infrared spectroscopy of the monolayer were employed to study the relationship between the metal and the peptide. Finally, Fe2O3 nanoparticles were incubated with the peptide, and analysis of the settling and particle size revealed that the presence of the peptide reduced the occurrence of large aggregates in solution. [ABSTRACT FROM AUTHOR]

Iridium dioxide, IrO 2 , is second to the most active RuO 2 catalyst for the oxygen evolution reaction (OER) in acid, and is used in proton exchange membrane water electrolyzers due to its high durability. To improve the activity of IrO 2 -based catalysts, we prepared RuO 2 @IrO 2 core-shell nanocatalysts using carbon-supported Ru as the template. At 1.48 V, the OER specific activity of RuO 2 @IrO 2 is threefold that of IrO 2 . While the activity volcano plots over wide range of materials have been reported, zooming into the top region to clarify the rate limiting steps of most active catalysts is important for further activity enhancement. Here, we verified theory-proposed sequential water dissociation pathway in which the O O bond forms on a single metal site, not via coupling of two adsorbed intermediates, by fitting measured polarization curves using a kinetic equation with the free energies of adsorption and activation as the parameters. Consistent with theoretical calculations, we show that the OER activities of IrO 2 and RuO 2 @IrO 2 are limited by the formation of O adsorbed phase, while the OOH formation on the adsorbed O limits the reaction rate on RuO 2 . [ABSTRACT FROM AUTHOR]