| 摘要 |
PURPOSE: Disclosed are an oxidation catalyst for methane in a rarefied concentration and preparing method thereof. CONSTITUTION: The oxidation catalyst is composed of Pt, Pd, Rh, or Au as active species and zeolite as catalytic support. The support uses one of H- or Na-type MFI, BEA, or USY structure ion-exchanged with ammonium or hydrogen ion and the ratio of Si to Al is 10-100. Prior to impregnation of active species on the support, organic compounds such as tetra propyl ammonium hydroxide (TPAOH), tetrabutylammonium hydroxide (TBAOH), tetrabutyl ammonium bromide (TBABr), or tetra-propyl ammonium bromide (TPABr) may be used to fill fully in the pore of the support with 0.3-10 ml/g-support. The noble metal species are used with 0.1-5 wt% amount based on the weight of zeolite by the impregnation method or the ion-exchange method. The catalyst is prepared by the dry of 100-150 deg.C for 3-5 h and the calcination of 500-600 deg.C for 3-6 h. The optimal reaction condition is 10,000-50,000 h-1 of space velocity, 210-400 deg.C of reaction temperature, and 30-500 ppm of methane concentration.
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