Singular modification effects of metal cations and metal complex ions on the catalytic properties of metal colloidal nanocatalysts

A series of selective hydrogenation reactions, cinnamaldehyde to cinnamyl alcohol, crotonaldehyde to crotyl alcohol, citronellal to citronellol, and o-chloronitrobenzene to o-chloroaniline, were studied over polymer-stabilized nanoscale noble metal colloid catalysts in solutions. Metal cations and metal complex ions significantly affected the catalytic performances of the noble metal colloidal nanocatalysts. Some metal cations increased both the activity and the selectivity of the nanosized catalysts, and metal complex ions exhibited more complicate effects.

Adsorbed metal cations motivates the polar CO group, then the nearby dissociated H atoms attack the C and O atoms of CO group to generate a hydroxyl group. This electron transfer from nanocatalyst to the adsorbed metal cation boosts the adsorbing ability of CO double bond onto the nanocatalyst surface, therefore increases the activity and the selectivity of nanocatalysts. Figure optionsDownload as PowerPoint slide