Thermal and chemical treatments were performed to significantly reduce impurities in scrap tire carbons (STCs) for preparation of highly-pure activated carbons.The STC sample was thermal treated at 800 ℃ for 2 h under a He gas flow of 45 sccm,followed by a treatment at 500 ℃ for 2 h under with a He/H2 (1/3) flow of 60 sccm.After the thermal treatments,the sample was refluxed in a diluted acid solution (HCl 2.0 M) at 100 ℃ for 4 h.