| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1994: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Active clusters of palladium oxide has been prepared in the pore structures of Y-zeolite by the R-O treatment consisted of three steps, calcination with O_2, reduction with H_2 and reoxydation with O_2. The catalytic behaviors of the cluster catalyst have been investigated in the partial oxidation of CH_4 into CO and H_2 and in the reduction of NO with C_3H_8 into N_2 and CO_2.
The Pd clusters catalyst showed high activities and excellent selectivities for both reactions. The mechanism of the reactions was investigated by temperature-programd and transient modes. In the main process of the former reaction, CH_4 in the gas phase reacts with oxygen species on the oxidized Pd surface. In the rate determining process of the latter reaction, on the other hand, carbonaceous species on the reduced surface from CH_4 reacts with NO in the gas phase. It was confirmed by EXAFS analyzes, furthermore, that under the operating conditions two kinds of Pd species (Pd and PdO) coexist in the pores and that they can function as catalytic centers via a reversible redox mechanism.
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