Yg. Zuo et Yw. Deng, IRON(II)-CATALYZED PHOTOCHEMICAL DECOMPOSITION OF OXALIC-ACID AND GENERATION OF H2O2 IN ATMOSPHERIC LIQUID-PHASES, Chemosphere, 35(9), 1997, pp. 2051-2058
Although the iron(III)-catalyzed decomposition of organic acids and fo
rmation of H2O2 in sunlit atmospheric water droplets has been well doc
umented, field measurements have shown that a large fraction of the di
ssolved iron in fogs, clouds, and rainwaters is present as reduced Fe(
II) species. In this study, we report on Fe(II)-initiated photochemica
l depletion of oxalic acid and formation of H2O2 in atmospheric water
droplets. Our results show that the Fe(II)/Fe(III) couple is involved
in the photocatalytic decomposition of oxalic acid and formation of H2
O2 with Fe(III) being the more active catalyst species. The initial ox
idation state of iron is not critical for the catalytical processes, s
ince the photochemical cycling between Fe(II) and Fe(III) occurs rapid
ly in the atmospheric droplets. (C) 1997 Elsevier Science Ltd.