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Mesoporous cubic PdxPt (x= 0.43-8.52) alloys with surface areas of 26-32 m(2)/g were synthesized using the KIT-6-templating method. Physicochemical properties of the materials were characterized by means of various techniques, and their catalytic activities were evaluated for methane combustion. It is found that the Pd and Pt were uniformly distributed in the PdxPt alloys. The addition of Pt to Pd exerted a significant effect on the redox property of Pd. The PdxPt alloys possessed a higher methane activation ability than the monometallic Pd. The oxidized Pd-Pt (i.e., PdO-PtO2) were more active than the metallic Pd-0-Pt-0. The Pd-2.41 Pt sample performed the best for methane combustion (T-10%, T-50%, and T-90% were 272, 303, and 322 degrees C at SV=100,000 mL/(gh); TOFpd, TOFpt, TOFpd+pt, and specific reaction rate at 280 degrees C were 0.85 x 10(-3) s(-1), 1.98 x 10(-3) s(-1), 0.59 x 10(-3) s(-1), and 4.46 mu mol(g(cat) s), respectively). The deactivation of the Pd-2,Pd-41 Pt sample induced by 2.5-5.0 vol% CO2 or H2O addition was reversible, but its deactivation due to 100 ppm SO2 introduction was irreversible. It is concluded that the excellent catalytic performance of the Pd-2,Pd-41 Pt sample was associated with its good mesoporous structure, Pd-Pt alloy and PdO-PtO2 coexistence, and good methane and oxygen activation ability. (C) 2017 Elsevier B.V. All rights reserved.
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