超临界CO2沉积技术制备负载钌炭催化剂

Preparation of Ru/C Catalysts by Supercritical CO2 Deposition

摘要:

以氯化钌为活性前驱体，活性炭为载体，采用超临界CO2沉积技术制备了负载钌/炭催化剂，以葡萄糖催化加氢反应考察了催化剂的活性，研究了助溶剂种类，助溶剂用量，超临界压力对催化剂活性的影响，并用SEM、XRD、XPS对催化剂表面的形貌、晶形及钌分布情况进行了表征。结果表明：超临界CO2沉积技术可有效提高负载钌炭催化剂的活性，在实验范围内，当助溶剂为甲醇，用量为2 ml，超临界CO2压力为12.0 MPa时制得催化剂的活性最佳，其催化活性是传统水浸渍方法制得样品的1.48倍；钌在催化剂中以无定型的非晶形式存在，钌在活性炭表面均匀分布，超临界沉积技术进一步增强了活性组分钌和载体间的相互作用。

Abstract:

Ru/C catalysts were prepared by supercritical CO2 deposition using RuCl3 as active precursor and activated carbon as support. The activity of Ru/C catalysts for hydrogenation of glucose were tested under 4.0 MPa and at 120 oC. The effects of the co-solvent category, co-solvent amount and supercritical CO2 pressure on catalytic activity were tested. The surface morphology, crystal form and Ru distribution of Ru/C catalysts were investigated by SEM, XRD and XPS. The results show that supercritical CO2 deposition technology can increase the activity of the Ru/C catalysts. In the experimental range, optimal activity of the catalysts can be obtained under the appropriate conditions of 2 ml methanol co-solvent and supercritical CO2 pressure 12.0 MPa. The highest reaction rate for hydrogenation of glucose exhibits 1.48 times higher than that of the catalyst prepared by the traditional method. Ru exists in the amorphous form in the catalysts with good dispersion on the activated carbon. Supercritical fluid deposition can enhance interaction between Ru and activated carbon.