1/26/2024 0 Comments Silica poisoningRay Harron face allegations in federal court leveled by CSX Transportation that the two conspired to create false asbestos exposure diagnoses for CSX employees. The Robert Peirce and Associates firm and Bridgeport radiologist Dr. Read more about how to correctly acknowledge RSC content.CHARLESTON - A Pittsburgh-based law firm and a West Virginia physician were part of an intricate web of deceit that led to big money for all, say their accusers in a civil fraud lawsuit. Permission is not required) please go to the Copyright If you want to reproduce the wholeĪrticle in a third-party commercial publication (excluding your thesis/dissertation for which If you are the author of this article, you do not need to request permission to reproduce figuresĪnd diagrams provided correct acknowledgement is given. Provided correct acknowledgement is given. If you are an author contributing to an RSC publication, you do not need to request permission Please go to the Copyright Clearance Center request page. To request permission to reproduce material from this article in a commercial publication, Provided that the correct acknowledgement is given and it is not used for commercial purposes. This article in other publications, without requesting further permission from the RSC, Tuller,Ĭreative Commons Attribution-NonCommercial 3.0 Unported Licence. Silica: ubiquitous poison of metal oxide interfacesĪ. We also take the opportunity in this review to more broadly introduce our recent findings regarding the critical role that the relative acidity or basicity of surface additives may have on hindering or accelerating the reaction kinetics on metal oxide surfaces, thereby providing a more detailed understanding of the reactivity of common poisons like silica in degrading device performance and means for combating their impact. Since a major focus of Professor John Kilner's research and publications have been concerned with chemical species that interfere with transport across grain boundaries and electrochemical reactions at metal oxide surfaces, including that of silica, we dedicate this review in his honour. chromia for solid oxide fuel cell cathodes, are known to be the sources of degradation of many functional electrochemical devices, the detailed mechanisms behind their effectiveness in depressing functionality remain controversial or poorly understood. Interestingly, while silica and other poisons, e.g. One omnipresent chemical species that appears to serve to “poison” the operation of many such electrochemical devices is some form of silica or SiO x, or in combination of other cations to form silicates. This may take the form of inert layers of materials that literally block access of oxygen, electrons or other reactive species to respective surfaces or interfaces or “poison” the catalytic activity of surface or interface sites needed for the efficient functioning of the devices. Understandably, any process that interferes with these surface or interface reactions is undesirable. Fuel cells require reduction of oxygen molecules at the cathode and subsequent incorporation into the electrolyte, diffusion across the electrolyte, (including across grain boundaries within the electrolyte) and subsequent oxidation of the oxygen ions at the anode and their exit back into the gas phase by reaction with reactive gas phase hydrocarbons or hydrogen to form CO, CO 2 and or H 2O. Semiconducting metal oxide (SMOX) sensors depend on the adsorption/diffusion of gas species on the surfaces or exposed grain boundaries and subsequent charge transfer between the semiconductor and the adsorbed gas atoms or molecules for their operation. As might be expected, surfaces and interfaces play key or essential roles in the operation of all of these types of devices. Examples include metal oxide gas sensors (semiconducting and electrolytic), solid oxide fuel and electrolysis cells, oxygen permeation membranes, oxygen storage materials and metal oxide-based catalysts. In this review, we consider electrochemical applications, broadly conceived, in which both ions and electrons play key roles in device operation and where exchange of oxygen between the gas and solid phase is likewise essential for operation.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |