Highly selective and stable hydrogenation of heavy aromatic-naphthalene over transition metal phosphides

The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides (MoP, Ni₂P, Co₂P, and Fe₂P) were prepared by wet impregnation and temperature-programmed reduction and characterized by x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), EDX mapping, scanning electron microscopy (SEM), transmission electron microscopy (TEM), brunauer-emmett-teller (BET), temperature-programmed desorption of ammonia (NH₃-TPD), and fourier transform infrared spectroscopy of pyridine (pyridine-FTIR). Of all the transition metal phosphides MoP was formed at a lower reduction temperature, which resulted in smaller particle size that enhanced the overall surface area of the catalyst. The existence of weak, moderate, and Lewis acidic sites over MoP were responsible for its high tetralin selectivity (90%) and stability during the 100 h reaction on-stream in a fixed-bed reactor.