生物形态多孔碳化硅催化载体的制备

玉米经高温热解转化为生物碳模板,通过液相渗硅反应制备了具有生物形态微观结构的多孔SiC催化载体材料。借助X射线衍射(XRD)和扫描电镜(SEM)对样品的物相和微观结构进行了表征,通过阿基米德法测定了产物的表观气孔率。实验结果表明,最终产物由β-SiC、Si和少量的α-SiC组成;多孔SiC遗传了玉米模板的蜂窝状多孔结构;随着起始硅碳比的增加,SiC含量和残余硅量均有所增加,生物碳模板向多孔SiC陶瓷的转变使显气孔率从93.14%降至86.03%。

Preparation of porous biomorphic porous silicon carbide from maize for catalyst support

Biomorphic porous SiC ceramics were produced from maize via replication method.The maize was first carbonized in inert atmosphere to obtain a biocarbon template, followed by reactive infiltration of the biocarbon preforms with liquid silicon at 1500℃.The microstructure morphology and component analysis of the cellular SiC were investigated by means of scanning electron microscope(SEM)and X-ray diffraction(XRD).The archimedes was used to test the apparent porosity of porous SiC ceramic.The samples consist mainly ofβ-SiC phase and Si phase and a littleα-SiC.The SiC replicas faithfully reproduced the macrostructure of maize and exhibited an open porosity 86.03%.