The influence of polyethylene glycol on the synthesis and activity of MoP for the hydrodechlorination of trichloroethylene

Molybdenum phosphide (MoP), synthesized by combining with polyethylene glycol (PEG), shows 4 to 5 times superior activity than conventional MoP for hydrodechlorination of trichloroethylene (TCE). We investigated the effect of PEG average molecular mass on the catalytic activity of MoP, and found that when the average molecular mass of PEG was 8000, the MoP catalyst gave the highest activity. Through X-ray diffraction (XRD), N2 adsorption–desorption, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and H2 temperature-program reduction (H2-TPR), the effect of PEG was investigated. The results showed that the addition of PEG changed MoP from the original flat structure to a lamellar structure, and indeed improved the growth of the (101) and (102) crystal planes (the possible crystal planes of high activity) and restrained the (100) and (201) crystal planes (the possible crystal planes of low activity). This leads to the high catalytic performance of MoP modified with PEG.