Formation of neutral and charged gold carbonyls on highly facetted gold nanostructures

Abstract

We show that gold mono- and di-carbonyls are formed on gold field emitter tips during interaction with carbon monoxide gas at room temperature and in the presence of high electrostatic fields. The experiments are done in a time-of-flight atom probe to obtain mass spectra. The yield of monocarbonyl cations is about twice that of di-carbonyl ions. Density functional theory calculations are reported that explain the field stabilization of adsorbed carbonyls and the desorption yield of their cations.

Formation of N2O and (NO)2 During NO Adsorption on Au 3D Crystals

“…In a previous PFDMS study of CO adsorption on Au [9] we have demonstrated the formation of AuCO and Au(CO) 2 singly or doubly charged ions suggesting CO twin bound at steps. The intensities of these species was found to depend strongly on the steady field strength applied between pulses and the data could be quantitatively assessed by DFT calculations.…”

The interaction of COO2 gas mixtures with Au tips: in situ imaging and local chemical probing

“…13 These calculations were performed along with an experimental study with PFDMS, which aimed at establishing relationships between the existence of gold carbonyl complexes and the static field strength on the tip. As in the case of oxygen, gold carbonyl formation is promoted by the presence of partial positive charges associated with a static (positive) electric field.…”

Dynamic Processes on Gold-Based Catalysts Followed by Environmental Microscopies

“…The initiation of the wave occurs close to the central pole, where the field is the highest, and then propagates away from the nucleation region down to the shank of the tip [201]. It has been shown that the application of an external field induces the presence of gold-carbonyls [199] but does not induce the adsorption/dissociation of oxygen species [200]. It is thus rather unlikely that the propagation wave corresponds to CO oxidation.…”

“…The study of CO adsorption on Au tips [199] suggests the formation of gold mono-and di-carbonyls, as shown in Figure 13b representing the mass spectra obtained during CO adsorption at room temperature. Gold carbonyls are indeed observed, in the presence of high electrostatic field, as AuCO + , AuCO 2+ and Au(CO) 2 + species.…”

“…The authors mainly observed the presence of a propagating wave during the imaging of the gold nanoparticle in the presence of CO + O 2 gas mixtures at 300 K. It has to be noted that FIM work during CO oxidation on Pt field emitter tips proved that oxygen is used as an imaging gas [198]. Since FIM imaging lacks chemical analysis, further studies coupling the FIM with mass spectrometry [148] were performed for different systems of increasing complexity: CO/Au [199], O 2 /Au [200] and finally CO + O 2 /Au [201].…”