Density Functional Theory Calculation and Experimental Study of Catalytic Synthesis SiC Nano Powders

作者：Wang Junkai; Han Lei; Huang Liang; Zhang Haijun^*; Li Junyi; Li Saisai

来源：Chemical Journal of Chinese Universities, 2017, 38(9): 1602-1610.

DOI：10.7503/cjcu20170259

• Density functional theory(DFT)
• 3C-SiC nano powders
• Catalytic carbonization reaction
• Silicon powder
• Phenolic resin

Taking Si-55, Si43M12 and Si37M18(M = Fe, Co or Ni) cluster as models, density functional theory (DFT) was used to investigate the catalytic mechanism of Fe, Co and Ni catalysts on the formation of SiC using Si and C as starting materials. The results show that Fe, Co and Ni nano catalysts will form alloy with Si first, and then elongate the bond length of Si-Si and weaken its bond strength, finally activate Si powder. The formation of alloy is favorable to the adsorption of C atom, and then accelerate the reaction process between Si and C atoms. The catalytic performance of Fe is better than Co and Ni. On this basis, 3C-SiC nano powders were synthesized by a microwave reaction method using silicon powders and phenolic resin as raw materials, and ferric/cobalt/nickel nitrate as catalyst precursor. The effects of catalyst type, heat treatment temperature, ;catalyst content and holding time on the preparation of 3C-SiC were investigated. Results indicated that the addition of Fe, Co and Ni significantly decreased the synthesis temperature of 3C-SiC. Si powder can completely transform into 3C-SiC at 1100 degrees C for 30 min using 2.0% Fe as catalyst. In contrast, for the sample without any catalysts, corresponding temperature was as high as 1250 degrees C. Moreover, the experiment results also indicated that the catalytic performance of Fe is better than Co and Ni, which is in consistent with the DFT calculations.

• 出版日期2017-9-10
• 单位武汉科技大学