Papers by Author: Hyun Chang Shin

Abstract: The physicochemical characteristics (SEM, N2 adsorption, FT-IR, MASNMR) of samples from kinetics (10 min, 20 min, 30 min, 1 h and 3h) of hydrolysis of tetraethyl orthosilicate (TEOS) gives new insight into the synthesis of nanosphere. The particle sizes are increased with time, however, the surface areas decreased. FT-IR investigation reveals the presence of high intensed silanol groups of 960 cm-1 at 10 min, which reduced on progress of the reaction time. This suggests the partial hydrolysis and condensation of alkoxy groups in TEOS. 29Si MASNMR analysis shows the presence three different silica species(Q4, Q3 and Q2) in 10 and 20 min samples. The intensity of Q2 species decreases with time and other species concentration were increased.

Abstract: The effect of various reaction factors such as amount of Ni loaded, temperature, and variety of supports on the methane conversion were investigated to obtain higher methane conversion. The high activities were observed over Ni(10 wt%)/SiO2 catalyst and at 650oC of reaction temperature. Catalysts using mesoporous supports such as SiO2 and MCM-41 showed good catalytic activity and stability.