Fig. 3: Characterization of 2.5Ru5Ni catalysts.
a HR-TEM images and corresponding FFTs of 2.5Ru5Ni after reaction. Colored lines correspond to different phases, with red indicating the likely location of RuNi alloys (blue: TiO2, yellow: unidentified amorphous phase). Unmodified and additional images are provided in Supplementary Fig. 22. b DRIFTS upon CO adsorption on 2.5Ru5Ni with monometallic counterparts added for reference. Band maxima associated with different CO adsorption modes are indicated. Conditions: mcat = 20 mg, FT = 15 cm3 min−1, T = 298 K. Evolution of bulk electronic structure and oxidation state obtained at different times during operation monitored by (c) normalized X-ray absorption near edge structure spectra corresponding to the Ru K-edge and (d) Fourier-transform EXAFS spectra at the Ru K-edge. Spectra recorded from a metallic ruthenium foil and from ruthenium oxide are added for reference. e Evolution of the main Ru reflection obtained at different times during operation monitored by X-ray diffraction. The symbol * indicates reflections corresponding to TiO2. The extended patterns are provided in Supplementary Fig. 26. The label “Fresh” refers to the state when the catalyst is loaded into the reactor, whereas 0.0 h refers to the moment when nominal pressure and reaction temperature have been reached. Reaction conditions: P(H2) = 20 bar, T = 523 K, catalyst/plastic = 1, feedstock = HDPE100. The subscripts x and y indicate relative metal content.
