The effects of hydrogen on KOH activation of petroleum coke

► The effects of H2 on KOH activation of petroleum coke (PC) were investigated. ► The addition of H2 enhanced the porosity development of the activated carbons. ► Additional CH and CH2 on the carbon precursors were formed in presence of H2. ► More K was formed during KOH activation in presence of H2. ► The activation was promoted by reaction of CH and CH2 with potassium compounds.