화학공학소재연구정보센터
Catalysis Today, Vol.45, No.1-4, 197-201, 1998
Syngas conversion using RhVO4 and Rh2MnO4 catalysts: Regeneration and redispersion of Rh metal by calcination and reduction treatments
The hydrogenation of CO over mixed oxides (RhVO4, Rh2MnO4) supported on SiO2 has been studied after H-2 reduction at 300 degrees C and at 500 degrees C, and the results compared with those of unpromoted Rh/SiO2 catalysts. Rh was more highly dispersed (40 Angstrom) after the decomposition of RhVO4 by the H-2 reduction than those of Rh2MnO4/SiO2 and unpromoted Rh/SiO2 catalysts. The activity and the selectivity to C-2 oxygenates of the mixed-oxide catalysts after the H-2 reduction were higher than those of the unpromoted Rh/SiO2 catalysts, but the activity of the RhVO4/SiO2 catalyst increased more dramatically after the decomposition by the H-2 reduction at 300 degrees C, and hence the yield of C-2 oxygenates increased. These results suggest that a strong metal-oxide interaction (SMOI) was induced by the decomposition of the mixed oxides after the H-2 reduction. The catalytic activity and selectivity were reproduced repeatedly by the calcination and reduction treatments of the spent (used) catalyst because of the regeneration of RhVO4 and redispersion of Rh metal.