Advanced Characterization Techniques Reveal Structure and Properties of Ruthenium Catalysts

Powder X-ray diffraction (XRD) analysis was conducted using a PANalytical X'Pert-Pro powder diffractometer in reflection mode with Cu Kα radiation (λ=1.5418 Å, 40 kV, 40 mA) to evaluate the bulk crystalline structure of the samples.

Transmission electron microscopy (TEM) images, along with energy-dispersive X-ray spectroscopy (EDS) mapping results, were obtained using a JEM-2100 microscope operating at 200 kV. TEM was utilized to visualize the Ru particles, estimate their size and morphology. The average size of Ru species was determined based on the statistical analysis of 100 nanoparticles.

High-resolution transmission electron microscopy (HRTEM) was performed using a JEOL JEM-F200 microscope operating at 200 kV to obtain detailed images of the catalyst structure.

X-ray photoelectron spectroscopy (XPS) measurements were conducted on an Axis SUPRA+ XPS spectrometer with 225 W of Al Kα radiation. The binding energy of all spectra was calibrated using the C1s signal at 284.8 eV.

Temperature-programmed reduction with H2 (H2-TPR) experiments were carried out using a BSD-Chem C200 instrument to assess the reducibility of the catalysts. Prior to the test, the as-prepared sample (30 mg) was pretreated in an Ar atmosphere (30 mL/min) at 120 °C for 30 minutes. The catalyst was then heated from room temperature to 800 °C (10 °C/min) in a 5% H2/Ar gas mixture (30 mL/min). The hydrogen consumption during the process was estimated using a thermal conductivity detector (TCD).