淀粉基炭负载纳米铜催化合成碳酸二甲酯

以硝酸铜和可溶性淀粉为原料, 经过溶胶-凝胶化过程、高温炭化和KOH活化得到炭负载铜催化剂(Cu/C), 采用扫描电镜、透射电镜、X射线衍射、热重-差热分析仪、N₂吸附和CO程序升温脱附对催化剂结构进行了表征, 并考察了它在甲醇氧化羰基化合成碳酸二甲酯(DMC)反应中的催化活性. 结果表明, 活化温度和KOH用量对催化剂的表面结构及金属铜粒子尺寸影响显著, 当活化温度为850℃, KOH:C=1 (质量比)时, Cu/C催化剂的比表面积达到1690 m²/g, 铜纳米粒子平均晶粒尺寸为30.4 nm, 催化活性最高, DMC时空收率达到235.7 mg·g^-1·h^-1, 甲醇转化率和DMC选择性分别为1.6%和76.5%.

Synthesis of dimethyl carbonate over starch-based carbon-supported Cu nanoparticles catalysts

Carbon-supported Cu (Cu/C) catalyst was prepared from Cu(NO₃)₂ and starch, by the sol-gel method, subsequent high temperature carbonization and KOH activation. Catalyst samples were characterized by scanning and transmission electron microscopies, X-ray diffraction, thermogravimetric analysis, N₂ adsorption-desorption and CO temperature-programmed desorption. Their catalytic performance in the oxidative carbonylation of methanol to dimethyl carbonate (DMC) in a fixed-bed reactor was investigated. The activation temperature and KOH content greatly influenced the catalyst microstructure and catalytic performance. The Cu/C catalyst prepared at activation temperature of 850℃ and KOH/C mass ratio of 1 exhibited the best catalytic activity. Its specific surface area and mean Cu particle size were 1690 m²/g and 30.4 nm, respectively. The space time yield was 235.7 mg·g^-1·h^-1, and the methanol conversion and selectivity for DMC were 1.6% and 76.5%, respectively.