Publikationsdatum:
2019
Beschreibung:
〈p〉Hydrogen peroxide (H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉) synthesis generally requires substantial postreaction purification. Here, we report a direct electrosynthesis strategy that delivers separate hydrogen (H〈sub〉2〈/sub〉) and oxygen (O〈sub〉2〈/sub〉) streams to an anode and cathode separated by a porous solid electrolyte, wherein the electrochemically generated H〈sup〉+〈/sup〉 and HO〈sub〉2〈/sub〉〈sup〉–〈/sup〉 recombine to form pure aqueous H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 solutions. By optimizing a functionalized carbon black catalyst for two-electron oxygen reduction, we achieved 〉90% selectivity for pure H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 at current densities up to 200 milliamperes per square centimeter, which represents an H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 productivity of 3.4 millimoles per square centimeter per hour (3660 moles per kilogram of catalyst per hour). A wide range of concentrations of pure H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 solutions up to 20 weight % could be obtained by tuning the water flow rate through the solid electrolyte, and the catalyst retained activity and selectivity for 100 hours.〈/p〉
Print ISSN:
0036-8075
Digitale ISSN:
1095-9203
Thema:
Biologie
,
Chemie und Pharmazie
,
Informatik
,
Medizin
,
Allgemeine Naturwissenschaft
,
Physik
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