Three dimensional analysis of the local structure of Cu on TiO_2(100) by in-situ polarization-dependent total-reflection fluorescence XAFS

摘要

Cu K-edge XAFS of Cu/TiO_2(110) was measured by polarization-dependent total-reflection fluorescence XAFS technique. XAFS of [001], [11-(bar)0], and [110] directions were measured to elucidate the three-dimensional structure of Cu species on the TiO_2(110) surface prepared by the deposition of Cu(DPM)_2 followed by reduction by H_2. Simulation of the EXAFS functions as well as conventional curve fitting analysis revealed that plane Cu_(3-4) small clusters with similar structure to Cu(111) plane were formed by the reduction at 363 K. The small clusters converted into spherical metallic Cu particles by the reduction at 473 K.