Density functional studies of the chemisorption of CO on transition metal catalysts of Ru, Rh, Pd (I)

Using the M-4 (M = Ru, Rh, Pd) clusters as models, chemisorption of CO at t he top and bridge sites has been performed by Gaussian programs, at the DFT /LANL1DZ level. Metal-CO bonding and the influence of CO bond after chemiso rption CO have been studied, and the effects on the products of CO hydrogen ation have been inferred. The calculations have shown that all the CO bonds are wakened after adsorption. Ru catalyst weakens C-O bond the most largel y, Pd weakens C-O bond the least, and Rh lies between them. So it could be concluded that the products of CO hydrogenation have a trend to the hydroca rbons over the Ru catalyst, and the products are inclined to oxygenate over Pd, while there isn't obvious trend to the hydrocarbons and oxygenate on R h.