Preparation of carbon alloy catalysts from humic acid and their activities for the oxygen reduction reaction.

Carbon catalysts for the oxygen reduction reaction (ORR) were prepared from mixtures of humic acid and cobalt compounds. To examine the effects of cobalt and nitrogen on the ORR, cobalt phthalocyanine (CoPc), cobalt chloride (CoCl 2 ) and phthalocyanine (H 2 Pc) were mixed with the humic acid and carbonized at 800 °C. The carbons were washed with hydrochloric acid to remove metals on the surface of the carbons. The carbon prepared by mixing HA, CoCl 2 and H 2 Pc (HA–CoCl 2 –H 2 Pc) had the highest ORR activity, while the carbons, HA–CoPc and HA–H 2 Pc, had lower ORR activities. HA–CoCl 2 had moderate activity. The results imply that both of cobalt and nitrogen are important to obtain ORR catalysts with higher activities. A uniform distribution of Co atoms in the precursor is also important to obtain carbon alloy catalysts with higher ORR activities. TANSO 2015 (No. 267), 94–100. [ABSTRACT FROM AUTHOR]