A hydrogen-nitric oxide cell for the synthesis of hydroxylamine
- Tokyo Inst. of Tech. (Japan). Dept. of Chemical Engineering
A H{sub 2}-NO fuel cell was designed for the synthesis of hydroxylamine in the gas phase. The hydroxylamine produced was trapped in an aqueous solution of H{sub 2}SO{sub 4} held in a silica-wool disk used as an electrolyte barrier for H{sub 2} and NO. Among the cathode electrocatalysts tested, iron-phthalocyanine (Fe-Pc) impregnated in graphite was the most favorable one for selective synthesis of hydroxylamine. Active carbon and carbon whiskers used to support the Fe-Pc enhanced the formation of hydroxylamine remarkably. The carbon itself slightly catalyzed the formation of N{sub 2}O and NH{sub 3}. Excluding the effects of the support, Fe-Pc catalyzed the electrochemical synthesis of hydroxylamine with high selectivity ({approx} 100%). Applied voltage across the cell did not appreciably enhance the formation of hydroxylamine. The reaction under short-circuit conditions was most favorable for the synthesis of hydroxylamine. It is suggested that the reduction of NO occurs on the Fe{sup 2+} site of Fe-Pc with protons and electrons transferred from the anode. The very selective synthesis of hydroxylamine over Fe-Pc must be ascribed to an Fe{sup 2+} site isolated by phthalocyanine ring. This isolation prohibits both the formation of N{sub 2}O through the intramolecular elimination of H{sub 2}O from the adjacent NHO intermediates and the formation of N{sub 2} and NH{sub 3} through the breaking of N-O bonds.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 428161
- Journal Information:
- Journal of the Electrochemical Society, Vol. 143, Issue 11; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
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