Method of regeneration of a spent sulfuric acid catalyst from alkylation of olefins and alkanes via paired oxidation

A method of regeneration of a spent sulfuric acid catalyst from alkylation of olefins and alkanes, said spent sulfuric acid catalyst containing organic impurities and water, said method comprising:

• introducing said spent sulfuric acid catalyst into an electrolysis reactor containing an anode and a cathode,
• introducing air or O2-containing gas into said spent sulfuric acid catalyst, and
• supplying electricity to said anode and said cathode,
• wherein said cathode is an O2-diffusion cathode which is selected from porous lead, pore graphene, and gas-diffusion carbon-polytetrafluroroethylene cathode, and said air or O2-containing gas is introduced into said spent sulfuric acid catalyst through the O2-diffusion cathode, so that oxygen, and water and protons in the spent sulfuric acid catalyst undergo reduction reactions at the O2-diffusion cathode, forming oxidants of hydrogen peroxide and hydroxyl free radicals, and thus at least a portion of the organic impurities are decomposed via reactions with oxygen and the so-formed oxidants.