CO HYDROGENATION TOWARDS HIGHER ALCOHOLS CATALYZED ON SIO2-GRAFTED AND ZEOLITE-ENTRAPPED RU, CO AND RUCO BIMETALLIC CLUSTERS - THEIR EXAFS AND FTIR CHARACTERIZATION AND CATALYTIC PERFORMANCES
Gc. Shen et al., CO HYDROGENATION TOWARDS HIGHER ALCOHOLS CATALYZED ON SIO2-GRAFTED AND ZEOLITE-ENTRAPPED RU, CO AND RUCO BIMETALLIC CLUSTERS - THEIR EXAFS AND FTIR CHARACTERIZATION AND CATALYTIC PERFORMANCES, Topics in catalysis, 2(1-4), 1995, pp. 141-154
Some Ru and Co carbonyl clusters in zeolite pores such as Ru-3(CO)12/N
aY, [HRu6(CO)(18)](-)/NaY, [Ru-6(CO)lg](2-)/NaX, Co-4(CO)(12)/NaY and
Co-6(CO)(16)/NaY were prepared by the ship-in-bottle technique, and ch
aracterized by FTIR and EXAFS. The RuCo bimetallic carbonyl cluster wa
s prepared by reductive carbonylation of the oxidized RuCo/NaY, which
provides the proposed assignment to [HRuCo3(CO)(12)]/NaY. The tailored
Ru, RuCo and Co catalysts were prepared by H-2 reduction from the pre
cursors, e.g. Ru, RuCo bimetallic and Co carbonyl clusters impregnated
on SiO2 and entrapped in NaY and NaX zeolites. The RuCo bimetallic ca
rbonyl cluster-derived catalysts showed substantially higher activitie
s and selectivities for oxygenates such as C-1-C-5 alcohols in CO hydr
ogenation (CO/H-2 = 0.33-1.0, 5 bar, 519-543 K). By contrast, hydrocar
bons such as methane were preferentially obtained on the catalysts pre
pared from Ru-6, Ru-3 and Co-4 carbonyl clusters and provided lower CO
conversion and poor selectivities for oxygenates. The RuCo bimetals a
re proposed to be associated with the selective formation of higher al
cohols in CO hydrogenation.