超临界流体技术制备Ru/C催化剂的研究

The Research of Ru/C Catalyst in Supercritical Fluids

以活性炭为载体、氯化钌为活性前驱体,采用超临界CO2流体沉积技术制备了Ru/C催化剂,用葡萄糖加氢生产山梨醇反应考察催化剂的催化活性。用正交实验考察了温度、CO2的量和还原剂KBH4的量等因素对制备Ru/C催化剂催化活性的影响规律;用红外光谱(IR)和扫描电镜(SEM)对Ru/C催化剂样品进行了结构表征。结果表明:制备温度对Ru/C催化剂的性能影响较大,Ru/C催化剂制备的最优工艺为:颗粒炭为0.6000 g,RuCl3为0.1000 g,助溶剂甲醇的量为0.5 mL,温度为60℃,充CO2量为40 mL,还原剂KBH4的量为0.10 g。最佳催化剂的催化活性为28.3 mmol/(min.g),是传统制备催化剂的1.89倍;RuCl3与颗粒C的结合不是简单的物理粘合,而是发生了一定的化学作用,形成的Ru/C催化剂保持了炭颗粒原有的表面结构形貌,负载的钌分布十分均匀。

Activated carbon as a carrier,ruthenium chloride as the active precursor preparation for Ru/C catalyst using supercritical CO2 fluid deposition method.The catalytic activity of catalysts were studied by reaction of glucose hydrogenation to sorbitol.The effects of preparation condition for Ru/C catalyst,ie,temperature,the amount of CO2 and the amount of reducing agent KBH4,on activity of the Ru/C catalysts were investigated by orthogonal experiment.Ru/C catalyst samples were investigated by IR and scanning electron microscopy（SEM）.The results indicated that properties of the Ru/C catalysts were remarkably affected by temperature.The best process conditions of Ru/C catalyst was that activate carbon was 0.6000 g,RuCl3 was 0.1000 g,the amount of methanol cosolvent was 0.5 mL,the temperature was 60 ℃,CO2 volume was 40 mL,the amount of reducing agent KBH4 was 0.10 g.The best catalytic activity was 28.3 mmol/（min·g） which was 1.89 times than the traditional preparation of the catalyst.RuCl3 combination with the particulate carbon was not a simple physical adhesion,but rather a chemical reaction occurs,the formation of the Ru/C catalyst kept the original surface morphology of carbon particles,ruthenium of distribution was very uniform.