PNNL

Abstract

Gold clusters adsorbed with CO, Aum(CO)n- (m=2-5; n=0-7), were studied by photoelectron spectroscopy (PES). The first few CO adsorption was observed to induce significant red-shifts to the PES spectra relative to pure gold clusters. For each Au cluster, a critical CO number (nc) was observed, beyond which the PES spectra of Aum(CO)n- change very little with increasing n. nc was shown to correspond exactly to the available low coordination sites in each Au cluster. CO first chemisorbs to these sites and additional CO then only physisorbs to the chemisorption-sautrated Aum(CO)n-complexes.