Five cordierite-supported monolithic catalysts with different additives were prepared by vacuum wetness impregnation. All catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), temperature-programmed reduction (TPR), and Raman spectroscopy. These catalysts were also tested by the raw gas from biomass pyrolysis to contrast them in terms of catalytic performance and stability. Characterization results show the formation of Mo-Ni alloy in the reduced catalyst with Mo additive; however, the other additives in the reduced catalyst remain in oxidation state. TPR revealed a strong interaction between the active component and the additives, resulting in a decrease of reduction ability. The catalysts with additives were shown to perform more efficiently compared with the catalysts without additives. The catalyst with Mo additive exhibited the best performance, with its tar conversion and gas yield reaching 96.6% and 1.22 N m(3)/kg, respectively, at a weight hourly space velocity of 706 kg/(h.m(3)). The 1Mo3Ni1Co/Cor catalyst exhibited higher stability compared with 1Sm3Ni1Co/Cor because the tar conversion of the former remained higher than 90%, whereas that of the latter decreased to 73.1% after a 4 h catalysis. Coke deposits were formed on the surface of the 1Sm3Ni1Co/Cor catalyst, which mostly exhibited a graphite structure, as observed by Raman spectroscopy.