Supported molybdenum/molybdenum-phosphides as inexpensive catalysts for bio-oil hydrodeoxygenation (HDO) were in-house prepared using different support materials, i.e., Al2O3, activated carbon (AC), MgAl2O4, and Mg6Al2 (CO3)(OH)(16). The HDO activity of these catalysts were investigated using a 100 mL bench-scale reactor operating at 300 degrees C with an initial hydrogen pressure of 50 bar for 3 h with a pyrolysis oil (PO). The catalytic efficiencies for bio-oil HDO for the catalysts were compared with the expensive but commercially available Ru/C catalyst. Addition of small amount of P to the Mo catalysts supported on either AC and Al2O3 led to increased degree of deoxygenation (DOD) and oil yield compared with those without P. MoP supported on AC (MoP/AC) demonstrated bio-oil HDO activity comparable to the Ru/C catalyst. Furthermore, three AC-supported metal phosphides for PO HDO were compared under the same conditions, and they were found to follow the order of NiP/AC>CoP/AC>MoP/AC. (C) 2016 American Institute of Chemical Engineers AIChE J, 62: 3664-3672, 2016