Catalytic Reforming of Methanol in Biporous Molecular Sieves

• Main Authors: Kuan-Cheng Liu, 劉冠呈
• Other Authors: H. Paul Wang
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/01850915930496150079

碩士 === 國立成功大學 === 環境工程學系碩博士班 === 96 === It is extremely vital to know that the storage of fossil fuel on earth is finite; that is, it will be used up in the near future. Therefore, exploratory research in alternative or renewable energy attracted a great attention to reduce greenhouse effect and energy crisis. Methanol is a common chemical engineering material with advantages of low cost, high availability, and easier transportation than H2. Biporous molecular sieves (BPMS) with both micro- and meso- pores characteristics were synthesized at 413 K. The BET surface area of the BPMS is 649 m2/g. Copper-zinc oxides supported on BPMS were used to catalyze methanol steam reforming (MSR), methanol decomposition (MD), water-gas shift reaction (WGS), and methanol partial oxidation (MPO). Methanol can be catalytically reformed to yield H2 at 523-623 K on copper-zinc oxides supported BPMS. By XANES and EXAFS spectroscopies, it is clear that Cu(I) plays the most important role in the catalytic MSR reactions. The pore structure of the molecular sieve supports is also associated with the reaction path of the catalytic MSR process. The main reaction such as water-gas shift and methanol decomposition in the catalytic MSR process can proceed in the meso- and micro-pores of the BPMS, that also accounts for the fact of high reactivity, low Ea, and high yields of H2 on the copper-zinc oxides/BPMS. The MD reaction occurs mainly in the mesopores (BPMS and MCM-41) where the active site copper may be dispersed with ZnO. Copper in the confined channel system such as ZSM-5 may form clusters with a size of <5 Å. High yields of H2 from the catalytic MPO reaction have been found at T <573 K.