Selective CO adsorption using sulfur-doped Ni supported by petroleum-based activated carbon

•Sulfur-doped Ni adsorbent supported on activated carbon was synthesized.•The Ni adsorbent gave the highest CO adsorption capacity (6.56 mmol/g).•The Ni adsorbent had a high selectivity to CO from the mixed gas.•The CO adsorption and desorption could be repeated with stable performance.