CuZnMgAl觸媒製備方法對觸媒結構與甲醇轉化反應的影響

• Main Authors: MUHAMMAD MUSTAFIZUR RAHMAN BHUIYAN, 夏棋
• Other Authors: Shawn D. Lin
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/mvag5r

博士 === 國立臺灣科技大學 === 化學工程系 === 102 === Cu with/without Zn was loaded on γ-Al2O3, MgO, their mixture, and partially/completely decomposed MgAl hydrotalcite (HT) in this study to analyze the interaction mode of CuZn and the effect of presence of acid, base or combined acid-base substrates to methanol conversion (MC) and methanol synthesis (MS) by CO hydrogenation. The structural, electronic and acid-base properties were analyzed by XRD, XANES, EXAFS, TPR, TPD etc. Catalytic activity study was done by a micro-reactor GC system. Higher oxygenates (C2+) were detected by GC-MS analysis of condensates collected from GC effluents. The structures and methanol reaction performances of CuZnMgAl catalysts are significantly influenced by their preparation conditions. The amount of water loading during catalytic synthesis, the identity and source of substrate and pretreatment temperatures are determining parameters. Incipient-wetness impregnation proved unfavorable to combine CuZnMgAl into a functional unit to exhibit C-C bond formation activity from methanol. Wet-impregnation technique, on the other hand, affected oppositely on condition that Cu2+ (at least above 4%) and Cu0 mixture in CuZn and medium basic sites from substrates work together. Within these conditions, the activation energy of methanol synthesis lowers and the site time conversion of methanol enhances. Production of higher oxygenates with specific functional groups is possible by (1) variation of Cu2+/Cu0 composition within CuZn interaction by H2 reduction and (2) variation of HT structure by thermal treatment. These procedures could catalyze 1-hexanol, 1-butanol, 1,3-butanediol and several straight/branched ethers/esters from methanol and 1-butanol from ethanol in a continuous system. In a batch reactor system, methanol-propanol feed yielded iso-butanol. Partially decomposed hydrotalcite, obtained by calcination at 573 K, favored straight chain alcohols whereas that obtained by calcination at 673 K promoted branched ethers and esters along with diols.