H₂O₂ is manufactured by the electrolysis of 50% sulphuric acid.
Cathode: Lead
Anode: Platinum
Two electrodes are separated by a porous stone ware diaphram.
Anode product: Peroxy disulphuric acid
(H₂S₂O₈)
Cathode product: Hydrogen.
${\mathrm{H}}_2{\mathrm{SO}}_4\underset{ }{\overset{ }{\rightleftharpoons }}{\mathrm{H}}^{+}+{\mathrm{HSO}}_4^{-}$
At cathode: $2{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2$
At anode: $2{\mathrm{HSO}}_4^{-}\to {\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_8+2{\mathrm{e}}^{-}$
${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_8+2{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{H}}_2{\mathrm{SO}}_4+{\mathrm{H}}_2{\mathrm{O}}_2$