Cu-Mn-Zr复合催化剂制备及其催化氧化乙酸乙酯性能

采用溶胶凝胶法制备了4种不同金属摩尔比的Cu-Mn-Zr复合催化剂，利用BET、XRD和XPS对其进行了表征分析，通过固定床管式反应器评价了其对乙酸乙酯模拟气体的催化活性，定性测定了其催化反应降解产物.结果表明，Mn的加入增大了催化剂的比表面积和总孔容，催化剂的N₂吸附-解吸等温线为IV型.Cu-Zr（1：1）催化剂观察到氧化铜晶体和四方晶型氧化锆晶体，氧化铜晶体随着Cu比例的减小而降低，Mn的加入导致氧化锆晶体消失.催化剂无固定形态，呈现良好的分散性.增大Mn/Zr摩尔比能提高催化活性.Cu-Mn-Zr的适当组分比能提高其低温催化活性，其中Cu-Mn-Zr（1：1：1）催化剂的低温催化活性与CO₂的选择性较佳，在200℃时对CO₂的选择性达到96.7%.降解产物分析表明，乙酸乙酯降解中间产物有乙酸和乙醇，最终降解产物主要有CO₂和H₂O等.

Preparation of Cu-Mn-Zr composite catalyst and performance for catalytic oxidation of ethyl acetate

The new Cu-Mn-Zr composite catalyst with four molar ratios of different metals was prepared by sol-gel method. The catalysts were characterized by BET, XRD and XPS. The catalytic activity of Cu-Mn-Zr composite catalyst on the simulated gas of ethyl acetate was evaluated by a fixed bed tube reactor. The degradation products of the catalytic reaction were detected qualitatively. Addition of Mn significantly increases the specific surface area and total pore volume of the catalyst. The N₂ adsorption-desorption isotherm of the catalyst is type IV. Copper oxide crystals and tetragonal zirconia crystals in the Cu-Zr (1:1) catalyst were observed. The copper oxide crystals decreased with the decrease of Cu ratio, and the addition of Mn resulted in the disappearance of tetragonal zirconia crystals. The catalyst was amorphous and had good dispersibility. Increasing the Mn/Zr molar ratio reduces the binding energy and improves the catalytic activity. Cu-Mn-Zr composite catalyst had good low temperature catalytic activity for ethyl acetate, and the proportion of appropriate components will increase the catalytic activity of the catalyst. The catalyzed oxidation effect of Cu-Mn-Zr (1:1:1) catalyst for ethyl acetate was the best, and its selectivity of CO₂ reached 96.7% at 200℃. The analysis results of degradation products showed that the intermediate products of ethyl acetate degradation were acetic acid and ethanol, and the final degradation products were mainly CO₂ and H₂O.