Site‐selective XAFS spectroscopy tuned to surface active sites of Cu/ZnO and Cr/SiO 2 catalysts

XAFS (X‐ray absorption fine structure) spectra were measured by using the fluorescence spectrometer for the emitted X‐ray from sample. The chemical shifts between Cu 0 and Cu I and between Cr III and Cr VI were evaluated. Tuning the fluorescence spectrometer to each energy, the Cu 0 and Cu I site‐selective XANES for Cu/ZnO catalyst were measured. The first one was similar to the XANES of Cu metal and the second one was the 5 : 5 average of XANES for Cu I sites + Cu metal. The population ratio of copper site of the Cu/ZnO catalyst was found to be Cu metal : Cu 2 O : Cu I atomically dispersed on surface = 70(±23) : 22(±14) : 8(±5). Site‐selective XANES for Cr III site of Cr/SiO 2 catalyst was also studied.