Enhanced adsorption of bio-oil on activated biochar in slurry fuels and the adsorption selectivity

•Activated biochar can better adsorb bio-oil due to improved pore structure.•Biochar shows different adsorption selectivity on the components in bio-oil.•Developed pore structure enhances selective adsorption of aromatic compounds.•O groups facilitate adsorption selectivity on aromatics, acids and ketones.•High graphitization degree helps adsorb heavy components in bio-oil.