| 초록 |
One of the advantages of heteropolyacid (HPA) catalysts is that their catalytic properties can be easily controlled by replacing protons or by substituting one of the framework transition-metal atoms with different metals. In general, it is known that the substitution of vanadium into the framework results in the increase of redox property of the HPA catalyst. The oxidation of methacrolein into methacrylic acid was carried out to investigate the catalytic activities of two types of vanadium-containing HPAs, Keggin type H3+xPMo12-xVxO40 (x=0, 1, 2, and 3) and Wells-Dawson type H6+xP2Mo18-xVxO62 (x=0, 1, 2, and 3) HPAs. It was observed that the catalytic performance was well correlated with the redox property of the catalysts. Although the structures and characteristics of two types of HPAs were different, both series of HPA catalysts showed the same trend in the catalytic properties and catalytic activities with respect to the vanadium substitution (KOSEF R01-2004-000-10502-0). |
