Browsing by Author "Chen, Yun-Sheng"

Now showing 1 - 2 of 2

Ruthenium substituted pyrochlore metal oxide catalysts Y2Ce2-xRuxO7-delta (x=0-0.4) for oxidative steam reforming of ethanol
(2020-07-31)
Hsieh, Ho-Chen
;
Chen, Yun-Sheng
;
Weng, Sheng-Feng
;
Hsieh, Yu-Ping
;
Lee, Chi-Shen
Metal oxides Y2Ce2-xRuxO7-delta (x = 0-0.4) with partial substitution of Run+ cations in the host structure were synthesized to study their catalytic activity on oxidative steam reforming of ethanol (OSRE). The samples were characterized using X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and temperature-programmed reduction (TPR). The performances investigated by varied temperatures, Ru ion content, carbon-to-oxygen ratios and long-term stability. The lowest activation temperature on OSRE is 300 degrees C, which is significantly lower than that of La2Ce2-xRuxO7-delta (400 degrees C). The cell dimension of Y2Ce2-xRuxO7-delta was reduced compare to La2Ce2-xRuxO7-delta for the replacement of the Y3+ ion with La3+ ion. The reduced unit cell in the host structure not only increase the surface composition of the Ce4+ ions, but also induce the synergetic effect of Run+/Ru4+ (n > 4) and Ce4+/Ce3+, which lead to the enhanced OSRE activity. The optimized catalyst Y2Ce1.6Ru0.4O7-delta showed selectivity of hydrogen S-H2 = 84(4)% (Y-H2 = 2.5(1) mol/mol EtOH) and carbon monoxide S-CO = 48(1)% for long-term stability test at T = 300 degrees C, C/O = 0.5, and O-2/C2H5OH = 1.5. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Synthesis and Catalytic Performance of Y2Ce2-xRuxO7(x=0 similar to 0.4) on Autothermal Ethanol Steam Reforming Reaction
(2012-01-01)
Chen, Yun-Sheng
;
Lee, Chi-Shen
;
應用化學系
;
Department of Applied Chemistry
Pyrochlore phases of Y2Ce2-xRuxO7 (x=0 similar to 0.4) solid solutions were prepared with the sol-gel process and used as catalysts for the autothermal steam reforming of ethanol (AESR). The as-prepared samples were characterized with powder X-ray diffraction (PXRD), X-ray photoelectron spectra (XPS) and temperature-programmed reduction (TPR). The oxidation state of Ru ions was confirmed by XPS and TPR analyses. Tests of catalytic activity showed that the reforming performance of Y2Ce2-xRuxO7 catalysts was affected by the Ru ion content. The optimized catalyst was Y2Ce1.6Ru0.4O7 with hydrogen selectivity S-H2 similar to 98% (autothermal temperature similar to 700 degrees C and 100% ethanol conversion at C/O = 0.6).