Combined in situ QXAFS and FTIR analysis of a Ni phosphide catalyst under hydrodesulfurization conditions

► The mechanism of thiophene desulfurization on nickel phosphide on MCM-41 is proposed. ► Simultaneous transmission Fourier transform infrared spectroscopy and X-ray absorption spectroscopy were used. ► A nickel phosphosulfide is the active species, and tetrahydrothiophene is an intermediate. ► Transient measurements with quick X-ray absorption of 10 s per spectrum were applied.