POLY(QUINOXALINE)-LIKE CHARS AS ROOM-TEMPERATURE REDOX CATALYSTS

Heterocyclic chars that have molecular structures akin to that of polyquinoxaline (PQ) were prepared and studied. As expected these PQ-chars have good affinity for species such as organic and mineral acids, the halogens, organic halides, and heavy metal cations. Consistent with the assumed highly conjugated polycyclic, ladder-like structure, PQ-chars are rich in delocalized electrons. They sorb oxygen from the air readily, and cause oxidation of co-adsorbed species. When this is made to occur in the presence of a suitable solvent for the product of oxidation, the PQ-char serves as a very effective room-temperature catalyst. Examples of such catalyzed oxidations carried out in the presence of aqueous NaOH are the conversion of H//2S to polysulfides, and the conversion of NO//x to nitric acid.