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キーワード:
EMTREE drug terms: carbon; graphene; hydrogen peroxide; nanoribbon; oxygen; platinum; sulfur; zeolite
GEOBASE Subject Index: carbon; catalyst; degradation; dispersion; electrochemistry; nanoparticle; platinum; reduction; sulfur; three-dimensional modeling
EMTREE medical terms: Article; catalysis; catalyst; chemical structure; degradation; dispersion; electrochemical analysis; molecular stability; reduction; scanning transmission electron microscopy; transmission electron microscopy; vapor; X ray photoelectron spectroscopy
要旨:
Maximum atom efficiency as well as distinct chemoselectivity is expected for electrocatalysis on atomically dispersed (or single site) metal centres, but its realization remains challenging so far, because carbon, as the most widely used electrocatalyst support, cannot effectively stabilize them. Here we report that a sulfur-doped zeolite-templated carbon, simultaneously exhibiting large sulfur content (17 wt% S), as well as a unique carbon structure (that is, highly curved three-dimensional networks of graphene nanoribbons), can stabilize a relatively high loading of platinum (5 wt%) in the form of highly dispersed species including site isolated atoms. In the oxygen reduction reaction, this catalyst does not follow a conventional four-electron pathway producing H2O, but selectively produces H2O2 even over extended times without significant degradation of the activity. Thus, this approach constitutes a potentially promising route for producing important fine chemical H2O2, and also offers opportunities for tuning the selectivity of other electrochemical reactions on various metal catalysts.
