Supporting information

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1 Supporting information The Bifunctional atalyst of ore-shell Nanoparticles Socketed on Oxygen-Deficient Layered Perovskite for Soot ombustion: in-situ Observation of Synergistic Dual Active Sites Yi-Fei Sun a, Jian-Hui Li b,*, Ya-Qian Zhang a, Bin Hua a,*, Jing-Li Luo a,* a Department of hemical and Materials Engineering, University of Alberta, Alberta, anada, T6G 2V4. b National Engineering Laboratory for Green hemical Production of Alcohols-Ethers-Esters, ollege of hemistry and hemical Engineering, Xiamen University, Xiamen, hina, orresponding Author. * Jingli Luo(jingli.luo@ualberta.ca), * Bin Hua (bhua1@ualberta.ca), * Jianhui Li (jhli@xmu.edu.cn). 1

2 Experimental Procedure atalyst preparation Pr 0.5 Ba 0.5 MnO 3 with and without 10 mol% o dopant was prepared by a modified sol-gel method. After dissolving nitrate salts of Pr, Ba, o and Mn in distilled water with the addition of quantitative amounts of citric acid and ethylene glycol (mol ratio of metal ion:citric acid:ethylene glycol = 1:3:1.5), the ph of the solution was adjusted to ~8 by adding ammonium hydroxide. The solution was continuously stirred on a hotplate at 60 until the gel formed. The gel was slowly decomposed at 350 and calcined in air at 950 for 4 h. The fabricated materials were denoted as PBMo and PBMO, respectively. After sintering, the PBMo sample was treated in 10%H 2 -N 2 for 4 hours at 500 and 850, and the resulting treated samples were denoted as PBMo-500 and PBMo-850, respectively. The 10 mol% o supported on PBMO was also prepared by an impregnation method reported elsewhere 1, using o(no 3 ) 3 6H 2 O as the precursor. The fabricated samples were sintered at 950 for 4 hours and further reduced in 10% H 2 -N 2 at 850 for 4 hours for a parallel comparison. The final obtained catalyst was denoted as o/pbmo. atalyst characterization The phase structures of synthesized powders were identified using a Rigaku Rotaflex X-ray diffractometer (XRD) with u Ka radiation, and the data were analyzed using JADE software. X-ray photoelectron spectroscopy (XPS) was performed using a Kratos Analytical AXIS 165. A monochromatic Al Kα source (hν = ev) was used with a power of 210 W and a base pressure of Pa in the analytical chamber. Spectra were referenced to the 1s binding energy of ev and fitted using Gaussian-Lorentzian peak shapes and Shirley baselines. In-situ Raman characterization was performed using Renishaw R1000 and Dilor LabRam I microprobe Raman systems equipped with D detectors. The excitation wavelength was a 532 nm He-d laser with a power of 3 mw at the analysis spot. The samples (catalyst or catalyst soot mixture with weight of 100 mg) were placed in an in-situ chamber allowing the control of the temperature and the surrounding atmosphere. The Raman spectra of the catalyst were recorded at selected temperatures during this process. To ensure 2

3 the intensity and quality of the signal, the temperature was maintained at each temperature point for 10 min, and the integration time was selected as 5 s. The micromorphology of the materials was illustrated by a JEOL 6301F Scanning Electron Microscope (SEM). The environmental TEM analysis of the combustion process was performed in a Hitachi H-9500 with a 100 kv accelerating voltage, heating to 330 under air. A small amount of tight-contact-mode catalyst and soot was placed on the u-micro grid. This sample was placed in the sample holder, equipped with the furnace and temperature controller, and inserted in the TEM. First, oxygen was introduced into the environmental cell chamber by gradually increasing the pressure surrounding the u-micro-grid to 9 Pa, and then the chamber was heated to 500. atalyst performance evaluation atalytic soot oxidation was studied by thermogravimetric analysis on a DST-Q-600 instrument using commercially available carbon black (Sigma-Aldrich) as a substitute for diesel soot. For oxidizing soot, the mixture of soot and catalyst was heated at 5 /min from 30 to 800 in an air atmosphere. The weight ratio of the catalyst and soot with loose contact was approximately 90:10. The catalytic performance was evaluated based on the temperature points T 0 (ignition temperature), T 50 (50% of soot consumed) and T 100 (100% of soot consumed). The outlet gas compositions were analyzed by mass spectrometry using a Thermo star 301 mass spectrometer. The selectivity of O 2 was defined as the O 2 concentration divided by the sum of the O 2 and O outlet concentration. 3

4 Figure S1. (a) SEM image of PBMo; (b) TEM image of PBMo-850; (c) SEM image of PBMo

5 o (111) ubic H Hexagonal PBMo-850 Intensity (a.u.) PBMo-500 H H H H H H PBMo H H H Theta (degree) Figure S2. XRD patterns of fresh and reduced PBMo materials. 5

6 o 2p 3/2 o 0 o 3 O 4 PBMo-850 Intensity (a.u.) o 0 o 3 O 4 PBMo-500 o 3 O 4 PBMo Binding Energy (ev) Figure S3. XPS spectra of fresh and reduced PBMo materials. 6

7 Figure S4. Heat flow curves determined by TPO over various samples for soot oxidation. 7

8 Weight Percentage (%) PBMo-850 PBMo-500 o/pbmo arbon PBMo Temperature ( o ) Figure S5. TGA curves determined by TPO method over various samples for soot oxidation. 8

9 Figure S6. TEM images for soot oxidation over time on PBMo-850 sample physically mixed with soot at 500 with 9 Pa O 2, acquired over 30 min without beam focus. 9

10 Figure S7. The TEM of the soot diffusing process on PBMo-850 for 240 s at intervals of 60 s, at 500 with 9 Pa O 2. 10

11 O 1s bulk O 2- suface O 2- PBMo-850 Intensity (a.u.) bulk O 2- O 2-2,Osurface O 2- O 2-2,O- PBMo-500 bulk O 2- bulk O 2- PBMo Binding Energy (ev) Figure S8. O 1s transition in XPS experiments performed with fresh and reduced PBMo catalysts. 11

12 In Ar PBMo-500 Heat Flow (mv) arbon endo -1.5 PBMo PBMo-850 exo Temperature ( o ) Figure S9. Heat flow curves determined by TPO method over various samples for soot oxidation in Ar atmosphere. 12

13 100 arbon Weight Percentage (%) In Ar PBMo PBMo-850 PBMo Temperature ( o ) Figure S10. TGA curves determined by TPO method over various samples for soot oxidation in Ar atmosphere. 13