Degenerate explosion of oxyhydrogen gas at the third ignition limit initiated by the products of a heterogeneous reaction on an inactive catalyst (quartz)

The heating of the wall of a reactor at the third ignition limit was measured during induction and explosion. It is shown that the heat released during induction is approximately equal to the heat released during explosion. It is established that in the induction period and below the limit, the reaction rate changes by a factor of about 10 with a change in the order of consecutive supply of hydrogen and oxygen to the reactor. This means that in these cases, the reaction occurs mainly on the wall of the reactor. The total amount of hydrogen peroxide and the peroxide radical HO$_2$ below the third ignition limit was measured. It is shown that these intermediate products are formed in an autocatalytic heterogeneous reaction. It is established from the sum of the data from the experiments and the literature that an detonating gas explosion at the third limit is degenerate. The explosion is the result of accumulation and decay of the intermediate product in the gas, which is hydrogen peroxide produced mainly in the wall of the reactor.