Deactivation of Ni spinel derived catalyst during the oxidative steam reforming of raw bio-oil

•Deactivation dynamics of a Ni spinel bulk catalyst in the OSR of bio-oil at 700 °C.•The deactivation causes are coke (on Ni and on pores of support) and Ni sintering.•The main coke precursors are non-reacted oxygenates.•The average Ni particle size increases 67%, mainly at the beginning of the reaction.•Valuable results for kinetic modelling and scaling-up of the process.