Comparative Studies on Noble Metal Dispersion of Ru/C Catalyst Characterized by HAADF and TEM

The dispersion properties of noble metal in Ru/C catalyst were characterized by transmission electron microscopy (TEM) and high angle annular dark field (HAADF) methods respectively, and the two methods were compared. On the basis of identifying catalyst Ru particles, a method to characterize the dispersion properties of noble metals was proposed by means of average size and size distribution. The results show that HAADF method can distinguish the noble metal particles on the carbon support well, while a large number of Ru particles are omitted when by TEM method due to the weak mass thickness contrast of the sample, so HAADF characterization results are more reliable. Compared with TEM, the dispersion properties of catalyst are more comprehensive and accurate by HAADF method, and HAADF can overcome the shortcomings of chemical adsorption and TEM methods in characterizing the dispersion of noble metals, and can evaluate the dispersion of noble metals on carriers more intuitively and comprehensively. And HAADF method has greater application value and advantages for the catalysts that is difficult to distinguish carrier from noble metal nanoparticles by chemical adsorption and TEM methods.