깁사이트를 이용한 고기능 세라믹 촉매담체의 제조 |
박병기, 서정권1, 이정민1, 서동수 |
충남대학교 공과대학 재료공학과 1한국화학연구원 화학공정연구센터 |
Preparation of High-capacity Ceramic Catalytic Support from Gibbsite |
Byung-Ki Park, Jeong-Kwon Suh1, Jung-Min Lee1, Dong-Soo Suhr |
Department of Mater. Eng., Chung-Nam Nat. Univ. 1Center of Chem. Eng., Korea Res. Inst. of Chem. Tech. |
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ABSTRACT |
We prepared γ-alumina beads using the amorphous alumina, obtained by fast calcination of gibbsite, and its were immersed in aqueous solution of the mixture of 21.87% nitric acid and 28.57% acetic acid. The beads thus were hydrothermaly treated at 200$^{circ}$C for 3h, and were investigated changes of crystal, pore characteristics, $N_2$ adsorption and desorption isotherms, mechanical strengths and thermal resistance. Acicular platelet crystals of 0.1∼0.3${mu}$m were transformed into acicular boehmite crystals of 1∼2${mu}$m having the same crystal structure. Through this changes, we found that reversible phase transformation due to hydrothermal reaction took placed between boehmite and ${gamma}$-alumina. In comparison to the ${gamma}$-alumina bead before hydrothermal treatment, $N_2$ adsorption capacity was increased from 450㎖/g to 670㎖/g, and pore volume between 100${AA}$ and 1000${AA}$ was increased form 0.15㎖/g to 0.77㎖g, and mechanical strength was increased form 1.4MPa to 2.2MPa. Also, it showed the remarkable thermal resistance which sustained ${theta}$-alumina crystal structure and pores between 100${AA}$ and 1000${AA}$ at 1000$^{circ}$C in 40vol% steam. |
Key words:
Gibbsite, Amorphous alumina, Boehmite, ${\gamma}$-alumina, Catalytic support |
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