READ ME File For 'Combined spatially resolved operando spectroscopy: New insights into kinetic oscillations of CO oxidation on Pd/?-Al2O3' Dataset DOI: 10.5258/SOTON/DO857 ReadMe Author: Peter Wells, University of Southampton This dataset supports the publication: Ellie K. Dann, Emma K. Gibson, C. Richard A. Catlow, Veronica Celorrio, Paul Collier, Tugce Eralp, Monica Amboage, Christopher Hardacre, Cristina Stere, Anna Kroner, Agnes Raj, Scott Rogers, Alexandre Goguetb, and Peter P. Wells Combined spatially resolved operando spectroscopy: New insights into kinetic oscillations of CO oxidation on Pd/?-Al2O3 Journal of Catalysis https://doi.org/10.1016/j.jcat.2019.03.037 This dataset contains: Data supporting figures in the main text and ESI. The figures are as follows: Figure 2. Mass spectrometry analysis of exhaust gas from plug-flow reactor during CO oxidation temperature ramp experiment with 1%CO/3%O2/Ar over the Pd/?-Al2O3 catalyst, showing CO concentration (black), O2 concentration (red) and CO2 concentration (blue) calculated relative to inlet CO signal from mass spectrometry and measured internal catalyst temperature (orange, dashed). Figure 3. a) Pd K-edge XANES spectra of Pd/?-Al2O3 catalyst at position 8 (14.6 mm) in a plug-flow reactor under reactant (1% CO/3% O2/Ar) gas feed, before (green) and after (black) ignition for CO oxidation. Plotted together with ex situ measurements of Pd/?-Al2O3 catalyst after reduction treatment in 4% H2 at 100°C (red) and then exposure to 10% O2 at 100°C (blue) and b) difference spectrum of Pd K-edge XANES before and after ignition for CO oxidation. Figure 4. Operando DRIFTS spectra of Pd/?-Al2O3 catalyst in plug-flow reactor at position 8 (nearest the end of the catalyst bed) during reactant (1% CO/3% O2/Ar) gas flow at increasing temperatures. Figure 5. Bottom panel shows EDE Pd K-edge white line intensity (green) and DRIFTS CO adsorption intensity (purple) of catalyst Pd/Al2O3 at spatial position 8 (nearest to the reactor outlet) of the fixed catalyst bed in reactant (1% CO/3% O2/Ar) gas feed during temperature ramp experiment (100 - 135°C). Top panel shows the simultaneous end-pipe mass spectrometry signals for O2 (red), CO (black) and CO2 (blue) concentrations of the reactor exhaust. Figure 6. Bottom panel shows EDE Pd K-edge white line intensity (green) and DRIFTS CO adsorption intensity (purple) of catalyst Pd/Al2O3 at spatial position 1 (nearest to the reactor inlet) of the fixed catalyst bed in reactant (1% CO/3% O2/Ar) gas feed during temperature ramp experiment (100 - 135°C). Top panel shows the simultaneous end-pipe mass spectrometry signals for O2 (red), CO (black) and CO2 (blue) concentrations of the reactor exhaust. Figure 7. End-pipe mass spectrometry O2 concentration (red), DRIFTS CO adsorption intensity (blue) and EDE Pd K-edge white line intensity (black) at multiple spatial positions (achieved through a series of consecutive temperature ramp experiments) in the Pd/?-Al2O3 fixed catalyst bed from the front/inlet (top panel) to the end/outlet (bottom panel) during each temperature ramp experiment (100 - 135°C) during flow of reactant gas feed (1% CO/3% O2/Ar). Figure 8. Thermographic IR images of reactor during CO oxidation (1%CO/3%O2/Ar) at increasing temperatures (115 - 124°C). Gas flow from inlet (left) to the outlet (right), annotated with the temperature read from the internal thermocouple positioned in the catalyst bed. The location of the catalyst bed within the reactor is outlined by a white box. Figure S1. TEM images of supported PdO nanoparticle catalyst, 3wt% PdO/?-Al2O3. Figure S2. Pd K-edge XANES of calcined PdO/Al2O3 catalyst contained in operando XAFS/DRIFTS reactor under reac-tant (1%CO/3%O2/Ar) gas feed at 100°C during exposure to EDE beam as a test for photoreduction, showing initial (0 secs, black dashed) and 500th (500 secs, red solid) accumulation at three different spatial positions. Figure S3. a) Pd K-edge EXAFS data of of Pd foil collected at I20-EDE, with k-weighting of 2. b) Stacked plot of non-phase corrected Fourier transformed EXAFS data, showing magnitude (top) and imaginary (bottom) part plotted with a fitting model (red, dashed) constructed from a single Pd-Pd scattering path. Figure S4. Mass spectrometry analysis of exhaust gas from plug-flow reactor during eight repeated CO oxidation temperature ramp experi-ments with 1%CO/3%O2/Ar over the Pd/Al2O3 catalyst, showing CO consumption (black), O2 consumption (red) and CO2 formation (blue) calculated relative to the inlet CO signal, and the measured internal catalyst temperature (orange, dashed). Position 1 to position 8 refer to the increasing distance from the front of the catalyst bed; 0.4, 1.8, 5.2, 7.1, 8.7, 10.4, 12.5 and 14.6 mm. Figure S5. k2 weighted Pd K-edge EXAFS data of Pd/?-Al2O3 catalyst positioned at the end of the catalyst bed (+14.6 mm from front of catalyst bed) a) in reducing atmosphere (4%H2/Ar) at 100°C and b) in CO/O2 reaction conditions at 114°C before light off, reaction time 1450 seconds Figure S6. k2 weighted Pd K-edge EXAFS data of Pd/?-Al2O3 catalyst positioned at the end of the catalyst bed (+14.6 mm from front of catalyst bed) a) in oxygen atmosphere (10%O2/Ar) at 100°C and b) in CO/O2 reaction conditions at 114°C after light off, reaction time 1460 seconds Figure S7. Non-phase corrected Fourier transformed Pd K-edge EXAFS data of Pd/?-Al2O3 catalyst, showing magnitude (top) and imaginary (bottom) a) in a reducing (4%H2/Ar) environment at 100°C, and b) positioned near outlet of plug-flow reactor in reactant (1%CO/3%O2/Ar) gas feed at 114°C before light-off for CO oxidation(reaction time 1450 seconds), plotted with a fitting model constructed from a single Pd-Pd scattering path. Figure S8. Non-phase corrected Fourier transformed Pd K-edge EXAFS data of Pd/?-Al2O3 catalyst,, showing magnitude (top) and imaginary (bottom) a) in an oxidising (10% O2/Ar) environment at 100°C, and b) positioned near outlet of plug-flow reactor in reactant (1%CO/3%O2/Ar) gas feed at 114°C after light-off for CO oxidation (reaction time 1460 seconds), plotted with a fitting model constructed from Pd-Pd and Pd-O scattering paths. Figure S9. Linear combination analysis of Pd/?-Al2O3 catalyst at the end of the catalyst bed, position 8 (nearest reactor outlet), dur-ing CO oxidation (1%CO, 3% O2) temperature ramp experiment. Linear combination fittings used two reference spectra to represent Pd(0) and Pd(II). Pd(0) used a spectrum of the Pd/?-Al2O3 catalyst in reducing H2/Ar atmosphere at 100°C. Pd(II) used a spectrum of the initial calcined catalyst PdO/?-Al2O3 in Ar at room temperature. Figure S10. a) (top panel) Pd K-edge XANES spectra of Pd/Al2O3 catalyst at position 1 (0.4 mm) in a plug-flow reactor under reactant (1% CO/3% O2/Ar) gas feed before (green) and after (black) ignition for CO oxidation. Plotted together with ex situ measurements of Pd/Al2O3 catalyst after reduction treatment in 10% H2 at 100°C (red) and then exposure to 10% O2 at 100°C (blue) and b) (bottom panel) difference spectra of Pd K-edge XANES before and after ignition for CO oxidation at positions 1 (black) and 8 (brown, dotted). Date of data collection: September 2015 - September 2018 Information about geographic location of data collection: University of Southampton, U.K. Dataset available under a CC BY 4.0 licence Publisher: University of Southampton, U.K. Date: April 2019