caa a22 4500 606173986 CHVBK 20210128100735.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s11244-014-0351-z doi (NATIONALLICENCE)springer-10.1007/s11244-014-0351-z Structural Analysis of Rh-Pd/CeO2 Catalysts Under Reductive Conditions: An X-ray Investigation [Elektronische Daten] [M. Scott, G. Waterhouse, K. Kato, S. Chang, H. Idriss, T. Söhnel] X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) were used to probe the electronic and geometric structures of Rh-Pd/CeO2 catalysts before and after ethanol steam reforming (ESR) at 400°C, as well as after heating in CO atmospheres as a function of time and temperatures. The O/Ce ratio determined by XPS for the as-prepared Rh-Pd/CeO2 catalysts (individual metal loadings of 0.5 or 2wt%) were close to 2, with the Rh and Pd present primarily in oxidized form (as oxide and chloride surface species). After ESR at 400°C the ceria support was heavily reduced to CeO2−x (x=0.3-0.4), with Rh0 (64% of total Rh) and Pd0 (67% of total Pd) being the dominant species. Heating the as-prepared Rh-Pd/CeO2 catalysts under a CO atmosphere at 200-400°C while monitoring the Pd and Rh K edges by XAS was also conducted. XAS of the K edge of Pd and Rh indicated, as expected, reduction of Pd before that of Rh from 200°C onward. The FCC order of Pd is however perturbed at 400°C. On the contrary, Rh once reduced maintained a well ordered (FCC) structure. This observation is rationalised by the greater reduction effect of Pd on CeO2 compared to Rh and therefore at the interface Pd structure may be altered at high temperatures. Springer Science+Business Media New York, 2014 In-situ CO reduction nationallicence Rh and Pd XANES nationallicence Rh and Pd XPS nationallicence Bimetallic catalysts nationallicence Ethanol steam reforming (ESR) nationallicence CeO2 HRTEM nationallicence Scott M. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut Waterhouse G. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut Kato K. JASRI/SPring-8, 1-1-1 Kouto, Sayo, 679-5198, Sayou-gun, Hyogo, Japan aut Chang S. School of Chemistry, Monash University, 3800, Melbourne, VIC, Australia aut Idriss H. Saudi Basic Industries Corporation (SABIC), CRI at KAUST, P.O. Box 4545-4700, Thuwal, Saudi Arabia aut Söhnel T. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut Topics in Catalysis Springer US; http://www.springer-ny.com 58/2-3(2015-03-01), 123-133 1022-5528 58:2-3<123 2015 58 11244 https://doi.org/10.1007/s11244-014-0351-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11244-014-0351-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Scott M. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut NATIONALLICENCE 700 1- Waterhouse G. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut NATIONALLICENCE 700 1- Kato K. JASRI/SPring-8, 1-1-1 Kouto, Sayo, 679-5198, Sayou-gun, Hyogo, Japan aut NATIONALLICENCE 700 1- Chang S. School of Chemistry, Monash University, 3800, Melbourne, VIC, Australia aut NATIONALLICENCE 700 1- Idriss H. Saudi Basic Industries Corporation (SABIC), CRI at KAUST, P.O. Box 4545-4700, Thuwal, Saudi Arabia aut NATIONALLICENCE 700 1- Söhnel T. School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand aut NATIONALLICENCE 773 0- Topics in Catalysis Springer US; http://www.springer-ny.com 58/2-3(2015-03-01), 123-133 1022-5528 58:2-3<123 2015 58 11244