Electrochemical reduction of CO presents an attractive way to store renewable energy in chemical bonds in a potentially carbon-neutral way. However, the available electrolyzers suffer from intrinsic problems, like flooding and salt accumulation, that must be overcome to industrialize the technology. To mitigate flooding and salt precipitation issues, researchers have used super-hydrophobic electrodes based on either expanded polytetrafluoroethylene (ePTFE) gas-diffusion layers (GDL's), or carbon-based GDL's with added PTFE.
View Article and Find Full Text PDFElectrochemical water splitting is one of the most sustainable approaches for generating hydrogen. Because of the inherent constraints associated with the architecture and materials, the conventional alkaline water electrolyzer and the emerging proton exchange membrane electrolyzer are suffering from low efficiency and high materials/operation costs, respectively. Herein, we design a membrane-free flow electrolyzer, featuring a sandwich-like architecture and a cyclic operation mode, for decoupled overall water splitting.
View Article and Find Full Text PDFWe discuss the latest developments in alternative battery systems based on sodium, magnesium, zinc and aluminum. In each case, we categorize the individual metals by the overarching cathode material type, focusing on the energy storage mechanism. Specifically, sodium-ion batteries are the closest in technology and chemistry to today's lithium-ion batteries.
View Article and Find Full Text PDFThe 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.
View Article and Find Full Text PDFAn efficient metal-free procedure for the formal α-carboxylation of primary alcohols has been developed. The method involves a one-pot oxidation/Passerini/hydrolysis sequence and provides access to α-hydroxy acids bearing a broad range of functional groups. A minor modification to the reaction conditions extends the range of accessible products to α-hydroxy esters.
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