【作者】 吴再国；

【导师】 刘化章； 岑亚青；

【作者基本信息】 浙江工业大学 ， 工业催化， 2007， 硕士

【摘要】 甲醇是一种极其重要的化工原料，同时又是一种潜在的代用清洁燃料。铜基甲醇合成催化剂具有低温低压高活性等特点，然而仍存在抗毒性差、热稳定性及机械强度差、使用寿命短等方面的问题。采用酸．碱交替沉淀法（AP法）制备的铜基甲醇合成催化剂，具有较高的活性和耐热性。本文在小试研究的基础上，考察了催化剂制备的放大效应，同时考察了催化剂的稳定性，以期将这种新型铜基甲醇合成催化剂实现工业化。考察了制备条件对催化剂活性和耐热性的影响。催化剂制备条件优化后如下：搅拌速度为250r／min，溶液滴加速度为200ml／min，盐碱溶液浓度都为1.0mol／1，沉淀温度为70℃，pH值摆动范围为5.0-9.5，交替沉淀次数为3次，老化时间为2h，焙烧温度为350℃。考察了催化剂制备的放大效应，并与国内外工业催化剂进行比较。催化剂制备量放大100倍后，活性和耐热性基本保持不变，催化剂物相、比表面积和表面颗粒形貌无明显变化。催化剂放大样（500g）初活性比国内工业催化剂X-98和CN分别高24.4％和26.8％，比DM高3.3％；耐热后活性比X-98和CN分别高24.8％和28.6％，比DM高17.1％。考察了催化剂的稳定性。催化剂在反应556h后无明显失活。这是因为催化剂中铜锌组分基本上形成了无定形状态的铜锌固溶体，铜锌组分间作用较强，还原后Cu晶粒较好地分散在ZnO晶格中，且铜晶粒较小。催化剂中较强的铜锌组分间作用，可以有效地抑制铜晶粒的增长，防止团聚以及热烧结现象的发生。采用氧-化学吸附H₂-TPR技术测定铜分散度，并对表征条件进行了优化。采用纯氢、5K／min的H₂-TPR升温速率和10％的氧脉冲浓度等表征条件对不同催化剂进行了铜分散度的测定，所得结果较好地反应了催化剂活性的变化规律，且能与XRD和BET等表征结果较好地关联。氧-化学吸附H₂-TPR技术是一种新型、有效的铜分散度表征方法。更多还原

【Abstract】 Methanol is not only an important fundamental material but also a potential cleaning fuel. Although copper-based catalysts have been used for many years with high activity and selectivity, but still exist many drawbacks, such as poor tolerance to poisoning, low thermal stability, low mechanical strength and short using life. The activity and thermal stability of catalyst prepared by precipitation method of alteration between acid and alkali were better. Based on this, the amount of catalyst was Scaled-up for 100 times. The preparation conditions was optimized and the stability of the catalyst was researched in the hope of appling this new copper-based catalyst into industrial production.The effect of preparation conditions on activity and thermal stability of catalyst were studied, the optimal preparation conditions were obtained as follows: the stirring speed was 250 r/min, the trickling speed was 200 ml/min, the concentration of alkali and metal solution were both 1.0 mol/L, the precipitating temperature was 70℃, the range of pH value was from 5.0 to 9.5, the alteration time was 3, the aging time was 2 h, and the calcination temperature was 350℃.There was no changes on activity and thermal stability of catalysts after scaling-up for 100 times, there was also no changes on crystal form and BET surface area of catalysts, it mean that the effect of scaling-up was eliminated effectively. The activity of catalyst（500 g） before thermal test was 24.4% higher than X-98, 26.8% higher than CN and 3.3% higher than DM; The activity of catalyst after thermal test was 24.8% higher than X-98, 28.6% higher than CN and 17.1% higher than DM.The stability of catalyst was studied. There was no obvious deactivation in catalyst after reacting for 556 h. Because the amorphous sosoloid of CuO and ZnO was formed, the effect between CuO and ZnO was strong, it can restrain the Cu crystallites increased in size effectively.The oxygen chemisorption H₂-TPR technique was optimized to determine the dispersion of Cu. Dispersions of Cu among several catalysts were measured with pure H₂, 5 K/min of heating rate and 10% pulse O₂. The result can show the change of the activity of catalyst effectively and relate the results of XRD and BET well. Oxygen chemisorption H₂-TPR technique is a new effective method to measure the dispersion of Cu.更多还原