Aluminum alloys play an important role in circular metallurgy due to their good recyclability and 95% energy gain when made from scrap. Their low density and high strength translate linearly to lower greenhouse gas emissions in transportation, and their excellent corrosion resistance enhances product longevity. The durability of Al alloys stems from the dense barrier oxide film strongly bonded to the surface, preventing further degradation.
View Article and Find Full Text PDFACS Appl Energy Mater
October 2020
Photoelectrochemical water splitting is a promising route to produce hydrogen from solar energy. However, corrosion of photoelectrodes remains a fundamental challenge for their implementation. Here, we reveal different dissolution behaviors of BiVO photoanode in pH-buffered borate, phosphate, and citrate (hole-scavenger) electrolytes, studied employing an illuminated scanning flow cell.
View Article and Find Full Text PDFWe introduce a new and straight-forward methodology to accurately determine the Pt content in polymer membrane electrolyte fuel cell (PEMFC) catalysts consisting of carbon supported Pt nanoparticles (Pt/C). The method is based on an indirect Pt proof (IPP) consisting of the oxidative removal of the carbon support, the digestion of the Pt in aqua regia followed by a replacement reaction to form Cu ions (CuCl). The Pt content is then determined via the Cu-ions with the help a complexometric indicator using a simple titration.
View Article and Find Full Text PDFIncreasing the catalyst's stability and activity are one of the main quests in catalysis. Tailoring crystal surfaces to a specific reaction has demonstrated to be a very effective way in increasing the catalyst's specific activity. Shape controlled nanoparticles with specific crystal facets are usually grown kinetically and are highly susceptible to morphological changes during the reaction due to agglomeration, metal dissolution, or Ostwald ripening.
View Article and Find Full Text PDFIn searching for alternative oxygen evolution reaction (OER) catalysts for acidic water splitting, fast screening of the material intrinsic activity and stability in half-cell tests is of vital importance. The screening process significantly accelerates the discovery of new promising materials without the need of time-consuming real-cell analysis. In commonly employed tests, a conclusion on the catalyst stability is drawn solely on the basis of electrochemical data, for example, by evaluating potential-versus-time profiles.
View Article and Find Full Text PDFTin-based oxides are attractive catalyst support materials considered for application in fuel cells and electrolysers. If properly doped, these oxides are relatively good conductors, assuring that ohmic drop in real applications is minimal. Corrosion of dopants, however, will lead to severe performance deterioration.
View Article and Find Full Text PDFDetermination of hydrogen in solids such as high strength steels or other metals in the ppb or ppm range requires hot-extraction or melt-extraction. Calibration of commercially available hydrogen analysers is performed either by certified reference materials CRMs, often having limited availability and reliability or by gas dosing for which the determined value significantly depends on atmospheric pressure and the construction of the gas dosing valve. The sharp and sudden appearance of very high gas concentrations from gas dosing is very different from real effusion transients and is therefore another source of errors.
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