An ab initio analysis of adsorption and diffusion of silver atoms on partially hydroxylated α-Al2O3(0001) surfaces

First-principles kinetics study of carbon monoxide promoted Ostwald ripening of Au particles on FeO/Pt(111)

“…Under reaction conditions, the adsorption of reactants on supported particles can lower the surface energy, influence the corresponding morphology [6][7][8] and even cause the wetting of metal particles on the supports [9,10] . In particular, adsorption of reactants on particles could weaken the metal-metal bonding of supported particles [11] , and facilitate the detachment/attachment of the metal monomer from/towards the particles, and stabilize the detached metal monomer by forming the metal-reactant complexes on the supports [12,13] . The presence of reactants may lead to the deactivation of supported particles because of promoted ripening via mass transport on the surface [14][15][16][17][18][19][20][21][22][23][24] or due to volatile loss [25] .…”

Formation, Migration, and Reactivity of Au–CO Complexes on Gold Surfaces

“…Previous studies have shown that strongly bound adsorbates often result in weaker metal–metal bonds and generate mobile metal–adsorbate complexes. − Direct evidence on the formation of CO–Pd complexes was found for Pd adatoms supported on a Fe 3 O 4 surface, and the important role of CO on the mobility and sintering for these CO–metal complexes was elucidated. , In a recent theoretical paper, Rousseau et al postulated that CO molecules bound to Au migrate not as individual CO molecules, but as a triatomic Au–CO complex. This would suggest the migration of Au–CO complexes with weaker Au–Au bonding and would be consistent with a number of other systems where adsorbate bonding generates mobile metal–adsorbated complexes, − or even organometallic structures on the surface of gold . An important question therefore is whether the CO that is present on the Au surface of the Au nanoparticle interacts with the gold lattice to create intermediate organometallic Au–CO x complexes.…”

The energies of formation and mobilities of Cu surface species on Cu and ZnO in methanol and water gas shift atmospheres studied by DFT

“…We show that the theoretical results are indeed consistent with the few experimental results on sintering of methanol synthesis catalyst. Our starting points are the two generic mechanisms for metal particle growth in heterogeneous catalysts [21][22][23][24]: (i) particle migration and coalescence (PMC) and (ii) Ostwald ripening (OR). In the former mechanism, entire metal particles are translated and eventually merge upon contact, whereas the latter mechanism is characterized by mass transport between the metal particles.…”