SELECTIVE SURFACE IMPREGNATION METHOD OF CATALYTIC MATERIAL VIA REPULSIVE FORCE AND SOLUBILITY DIFFERENCE BETWEEN HYDROPHILIC AND HYDROPHOBIC SOLVENTS AND CATALYST MADE THEREBY

摘要

The present invention relates to a method for preparing a catalyst in which a catalytically active substance is selectively impregnated or supported only on surface areas of catalyst particles by using a repulsive force and a solubility difference in a metal salt precursor between hydrophilic and hydrophobic solvents. For the hydrophobic solvent, alcohols such as propanol, butanol, pentanol, and hexanol may be used. The method for preparing a catalyst of the present invention introduces the hydrophobic solvent into a catalyst support, and then introduces a hydrophilic solution including the metal salt; therefore the hydrophilic solution is slowly diffused into the catalyst particles by a repulsive force against the hydrophobic solvent. As the catalyst support is supported by controlling the time since the diffusion rate is reduced, and then slowly dried, the catalytically active substance or a precursor making the catalytically active substance are selectively supported on the outside of the catalyst particles. Therefore, the method for preparing a catalyst of the present invention can prepare an egg-shell type catalyst in which the catalytically active substance is selectively supported only on the outer surface of the catalyst support particles.