Cu-Ni과 Ni촉매 하에서 상업용 프로판 가스를 분해시켜 화학증착법에 의해 미세탄소섬유의 제조 조건을 확립하기 위하여 촉매의 조성, 반응온도, 가스유량 등 실험조건을 변화시켜 보았다. SEM관찰을 통해 형성된 carbon deposits가 대부분 직경이 50-300nm정도되는 미세섬유의 형태임을 알 수 있었고, 촉매의 조성과 온도 변화에 따라 수율과 섬유의 구조가 다르게 얻어졌다. 보통 650-700℃의 반응온도에서 가장 높은 수율을 얻을 수 있었으며, 순수 Ni촉매보다는 Ni의 조성이 50-90 wt%인 Cu-Ni 합금촉매에서 높은 수율이 얻어졌다. 전기이중층 캐패시터의 분극성 전극의 성능을 좌우하는 주요 물성인 비표면적과 전기 비저항값을 측정하였는데, Cu-Ni 합금촉매에서 생성된 미세탄소섬유의 비표면적은 대략 350 m²/g였고 Ni 촉매에서는 약 150 m²/g로 얻어졌다. 전기 비저항값은 0.05-0.25 Ω·cm의 범위에서 촉매의 조성에 따라 민감하게 변하였고, 기존의 원료인 활성탄보다 매우 낮은 값이었다.

In order to establish the reaction conditions for producing carbon nanofibers by passing a commercial propane gas over Cu-Ni and Ni catalysts, the experimental conditions such as catalyst composition, reaction temperature and gas flow rate were varied. It was observed by SEM that the obtained carbon deposits were mainly composed of carbon nanofibers with the diameters ranging 50-300 nm. The carbon yield and structure were dependent on the catalyst composition and reaction temperature. The maximum yields of carbon nanofibers from propane decomposition were obtained at temperatures from 650 to 700℃ and the higher yields were obtained over the alloy catalysts containing 50-90 wt% nickel than the pure nickel catalyst. The specific surface area and electric resistivity were measured as the key properties for the electrode application of a double layer capacitor(DLC). The carbon nanofibers from Cu-Ni catalyst had relatively high surface areas of around 350 m²/g, while those from Ni catalyst showed about 150 m²/g of surface areas. The electrical resistivity was also dependent on the catalyst composition, raging 0.05-0.25 Ω·cm and these values were much lower than those for activated carbon which is currently used as the electrode materials.

Carbon Nanofibers Double Layer Capacitor Cu-Ni Catalyst Electrical Resistivity

Rodriguez NN, J. Mater. Res., 8(12), 3233 (1993)
Baker RTK, Carbon, 27(3), 315 (1989) 
Kim MS, "Influence of Selected Metal Catalysts on Carbon Filament Formation," Ph.D. Thesis, Auburn University, Auburn, U.S.A. (1991)
Baker RTK, Barber MA, Harris PS, Feates FS, Waite RJ, J. Catal., 26, 51 (1972) 
Rostrup-Nielsen J, Trimm DL, J. Catal., 108, 155 (1977) 
Alstrup I, J. Catal., 109, 241 (1988) 
Bianchini EC, Lund CRF, J. Catal., 117, 455 (1989) 
정의남, 이학민, 제 1회 탄소재료의 개발과 응용에 관한 Workshop, 충남대, 대전, 95 (1995)
Rodriguez NM, Kim MS, Downs WB, Baker RTK, "Carbon Fibers Filaments and Composites," NATO ASI Series (Kluwer Academic Publishers, Dordrecht, The Netherlands), 177, 541 (1990)
Baker RTK, Yates DJC, "Coke Formation on Metal Surfaces," ACS Symposium Series 202, 1 (1982)
Rodriguez NM, Kim MS, Baker RTK, J. Catal., 140, 16 (1993) 
Espinola A, Miguel PM, Salles MR, Pinto AR, Carbon, 24(3), 337 (1986) 
Nishiyama Y, Tamai Y, J. Catal., 33, 98 (1974) 
Kim MS, Rodriguez NM, Baker RTK, J. Catal., 131, 60 (1991) 
Kim MS, Rodriguez NM, Baker RTK, "Synthesis and Properties of Advanced Catalytic Materials," (Iglesa, E., Thomson, L., Nagak, D. and Ledmar, P. ed), Materials Research Society, 368, 99 (1995)
Rodriguez NM, Proc. 19th Biennial Conference on Carbon, Penn. State University, University Park, U.S.A., 67 (1989)
Kim MS, Rodriguez NM, Baker RTK, J. Catal., 134, 253 (1992) 
Donnet JB, Voet A, "Carbon Black," Marcel Dekker, Inc. (1976)