多孔碳化硅材料的制备及其催化性能

Synthesis of Porous Silicon Carbide and Its Catalysis

以糊精作为造孔剂及粘结剂,制备出了多孔碳化硅陶瓷。通过调节添加剂的含量,得到空隙率27％～70％的多孔陶瓷体,孔径呈现出明显的双峰分布。应用XRD和SEM手段对多孔陶瓷的形貌以及结构的分析表明,不同的烧结气氛对材料有着很大的影响。比较了有氧气气氛和在真空条件下烧结的多孔碳化硅材料性能,气孔率从60％明显下降到28％,材料强度从24MPa上升到90MPa。对材料的催化性能表征显示,用多孔碳化硅作为碳改性的氧碳化钼(MoC_3-C)催化剂载体,具有较高的选择性,达到70％,但活性仅20％,其原因尚需进一步研究。

The processing and properties of porous silicon carbide were studied. The dextrin was used as pore-making agent and binder. The porous silicon carbide with a porosity from 27% to 70% was synthesized by adjusting the content of dextrin and at the same time the pore size and distribution of the specimen can be effectively controlled. XRD and SEM were carried out to characterize phases and microstructure of the specimen. The isomerization behavior of molybdenum oxycarbide supported on such material was studied. The selectivity of it is 70% for dodecane which is higher level compared to other porous materials. But the activity is only 20%. The reasons for this need to be further investigated.