Identification of active sites for hydrogenation over Ru/SBA-15 using in situ Fourier-transform infrared spectroscopy

The active sites for hydrogenation over Ru/SBA-15 catalysts were identified using in situ Fourier -transform infrared spectroscopy. The amount of active sites was proportional to the interfacial circumference of the Ru particles. In contrast, the rate of hydrogen spillover from Ru to the support was inversely proportional to the size of the Ru metal particles. Consequently, a catalyst with small Ru metal particles has a high rate of hydrogen spillover but a low density of active sites, whereas one with large Ru particles has a low rate of hydrogen spillover but a high density of active sites. The formation of these active sites is probably an intermediate step in hydrogen spillover. (C) 2016, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.