Insight into surface properties of O2 plasma activated Au/TiO2 prepared by DPU in CO oxidation

•Au/TiO2 prepared by DPU is explored to be activated by cold O2 plasma.•The poisoning nitrate species are observed over the plasma-activated catalyst.•The poisoning nitrate species are completely removed by further TPD treatment.•The plasma-activated catalyst with further TPD shows the superior catalytic activity.