Effect of pyrolysis oil components on the activity and selectivity of nickel-based catalysts during hydrotreatment

•The effect of the pyrolysis oil components on the HDO activity and selectivity of nickel catalysts was investigated.•Regenerated NiCu/Al2O3 after bio-oil hydrotreatment showed only marginal reduced HDO activity compared to the fresh catalyst.•During bio-oil hydrotreatment phenol conversion and hydrodeoxygenation of ketones were blocked.•The main influence to the catalyst activity and selectivity was attributed to sulphur, which formed Ni3S2 on the catalyst surface.