Fast pyrolysis oil (PO), the liquid product of fast pyrolysis of lignocellulosic biomass, requires upgrading to extent its application range and for instance to allow for co-feeding in an existing oil-refinery. Catalytic hydrotreatment reactions (350 degrees C, 20 MPa total pressure, and 4h reaction time) with mono- and bimetallic metal catalysts based on Rh, Pt, Pd on a zirconia support were performed in a batch set-up. Pd/ZrO(2) showed the highest activity, followed by Rh/ZrO(2). Upgraded oils with the best product properties were obtained with Rh/ZrO(2). For this catalyst, the TGA residue, which is a measure for coking tendency, was 13.4 wt% and the M(w) of the upgraded oil (748 g/mol) was lowest. All noble metal catalysts showed higher activities per gram of metal than the benchmark catalyst CoMo/Al(2)O(3). Hydrotreatment reactions at variable batch times were performed to gain insights in reaction pathways and showed the involvement of competitive hydrogenation/hydrocracking and polymerisation pathways. Temperature programmed oxidation (TPO) measurements of spent catalysts showed the presence of carbonaceous deposits on the catalyst (2-6 wt%). These deposits may be removed by oxidation at temperatures lower than 600 degrees C without changing the morphology of the catalyst. (C) 2011 Elsevier BM. All rights reserved.