催化剂对硅氧碳多孔陶瓷结构与性能的影响  

Structure and Properties of Silicon Oxycarbide Porous Ceramics with Different Catalysts

作　　者：王鹏 张军战[1] 张颖[1] 覃枫 杨明辉 陈红侠 Wang Peng;Zhang Junzhan;Zhang Ying;Qin Feng;Yang Minghui;Chen Hongxia(College of Materials Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,陕西西安710055

出　　处：《稀有金属》2022年第12期1573-1579,共7页Chinese Journal of Rare Metals

基　　金：国防科技重点实验室基金项目(614291104011317);陕西省重点研发计划项目(2020SF-426)资助。

摘　　要：分别采用氯化钴、乙酸镍、氯化铁和氯化钴-乙酸镍、氯化铁-乙酸镍、氯化铁-氯化钴作为单一金属催化剂和双金属催化剂,以硅树脂RSN-217作为陶瓷前驱体,聚甲基丙烯酸甲酯(PMMA)微球为造孔剂,在Ar气氛下于1400℃通过催化裂解原位生长SiC纳米线并制备SiC纳米线增强的硅氧碳(SiOC)多孔陶瓷,研究了催化剂种类对SiOC多孔陶瓷组成、结构、力学性能及电学性能的影响。结果表明,造孔剂的引入使得SiOC多孔陶瓷孔径大小一致,气孔分布均匀;催化剂的引入促进了SiC纳米线的原位生长,自由碳含量从11%(质量分数)提高到32%,显气孔率从46.2%降低到43.1%。对于原位生长SiC纳米线的效果而言,添加双金属催化剂最好,添加单一金属催化剂次之,不加催化剂的空白样最差,同样力学性能及电学性能也符合该变化规律。其中,由于添加氯化钴-乙酸镍的双金属催化剂原位生长的SiC纳米线数量多、长径比高,并均匀分布,因此该双金属催化剂为本文最佳催化剂,当显气孔率为43.1%时,与空白样相比,耐压强度从7.3 MPa提升至11.2 MPa,提高了53%;体积电导率从9.8×10^(-5)S·cm^(-1)增加到2.13 S·cm^(-1),提高了4个数量级。With excellent properties such as corrosion resistance,oxidation resistance,thermal stability and tunable functional properties,silicon oxycarbide(SiOC)porous ceramics were widely used in the fields of catalyst support,high temperature gas purification,microwave absorbing,electrode,and so on.The properties of SiOC porous ceramics could be further improved by introducing one-dimensional SiC nanomaterials,and thus the structure and function integration composites could be obtained.In this paper,taking RSN-217 silicone resin as the ceramic precursor and polymethyl methacrylate(PMMA)microspheres as pore-forming agent,SiC nanowires reinforced SiOC porous ceramics were prepared by the catalytic pyrolysis of silicone resin.To promote in-situ growth of SiC nanowires in SiOC porous ceramics,cobalt chloride,nickel acetate and ferric chloride were employed as single catalysts,and cobalt chloride-nickel acetate,ferric chloride-nickel acetate and ferric chloride-cobalt chloride as composite catalysts,respectively.The preparation processes were as follows.Firstly,RSN-217 silicone resin was pre-cured at 250℃.And then,the catalyst,pore-forming agent and pre-cured silicone resin powder were mixed uniformly in a certain ratio and mould pressed to shape.Finally,the green body was pyrolyzed in an alumina tube furnace and kept at 1400℃for 2 h in an argon atmosphere.The pore structures and the in-situ growth of SiC nanowires in SiOC porous ceramics prepared with different kinds of catalysts were observed by scanning electron microscope(SEM).The chemical compositions of the product were determined by energy dispersive spectrometer(EDS).The apparent porosity,compressive strength and volume resistivity of the porous ceramics were also characterized.The effects of different kinds of catalysts on the microstructure,mechanical property and electrical property of SiOC porous ceramics with in-situ growth of SiC nanowires were investigated.The main results and conclusions were as follows:Two types of pores in SiOC porous ceramics were obse

关 键 词：硅树脂 催化剂 催化裂解 SIC纳米线 SiOC多孔陶瓷 

分 类 号：TQ174[化学工程—陶瓷工业]