Direct Observation by EXAFS of Selenophene Chemisorption by Sulphide Hydrodesulphurization Catalysts

After adsorption of C₄H₄Se at ambient temperature, two intense peaks appeared in the radial atomic distribution curves obtained from the Ni K-edge EXAFS spectra of the sulphide catalysts Ni–Mo/Al₂O₃, which have been attributed to the coordination of selenophene to Ni with Ni–Se distance R 2.5 Å and Ni–C distance R 3.0 Å; no evidence for the coordination of selenophene to Mo was obtained from Mo K-edge EXAFS.