A study of sensitized explosions I- The hydrogen oxygen reaction catalysed by nitrogen peroxide

Abstract

The catalysis of the combustion of hydrogen and oxygen by nitrogen peroxide was first discovered by Dixon, and later studied quantitatively by Gibson and Hinshelwood, Thompson and Hinshelwood, and by Norrish and Griffiths. Thompson and Hinshelwood found that the ignition temperature of hydrogen was depressed by over 100° C by the addition of less than 0·1% (0·1 mm) of nitrogen peroxide, but that this sensitized ignition was confined within a narrow range of pressures of nitrogen peroxide, the upper limit increasing with rise of temperature and decreasing with increasing pressure, whilst the lower limit was only slightly affected. Norrish and Griffiths found that, within similar limits of pressure of nitrogen peroxide, rapid reaction but no explosion occurred when an axial tube was used for the inlet of gas. This reaction was accelerated by irradiation with light which decomposes nitrogen peroxide to nitric oxide atomic oxygen, but not by light which is absorbed without producing photochemical decomposition. Without the axial tube, explosions occurred, but the ignition temperature was not affected by irradiation.