[Display omitted] • Unsupported Ni, Co, and Cu phosphides catalysts were prepared by precipitation method. • Ni 2 P + Ni 12 P 5 (Ni x P y), Co 2 P, and Cu 3 P phases were obtained after reduction in H 2. • Green diesel (GD) yield was in the order of Ni x P y > Co 2 P > Cu 3 P. • The major products were straight-chain alkanes with C 15 -C 18 from all catalysts. • The Ni x P y gave better the hydrodeoxygenation products than the commercial Ni 2 P. This work aims to investigate the catalytic hydrodeoxygenation (HDO) of palm oil to produce green diesel (GD) on phosphides of nickel (Ni), cobalt (Co), and copper (Cu) without support materials. The metal phosphides were obtained by co-precipitation of metal precursors and phosphoric acid followed by calcination and reduction with hydrogen. The as-synthesized, calcined and reduced samples were characterized by various modes of X-ray absorption spectroscopy (XAS) including time-resolved X-ray absorption (TR-XAS), X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), and X-ray diffraction (XRD). The phosphide phases of Ni, Co and Cu after reduction were mixed-phase Ni 2 P and Ni 12 P 5 (denoted as Ni x P y), Co 2 P and Cu 3 P, respectively. Their catalytic performance was determined in a continuous fixed-bed flow reactor under H 2 atmosphere at 300, 350 and 400 °C for 6 h. The best catalyst was Ni x P y providing the highest GD yields. The main catalytic route was decarbonylation (DCO) yielding C 15 + C 17. The minor routes were decarboxylation (DCO 2) and HDO. Moreover, Ni x P y provided better yields of all products than the commercial single-phase Ni 2 P. [ABSTRACT FROM AUTHOR]