Theoretical insights on the effect of reactive gas on the chemical ordering of gold-based alloys

Abstract

Alloy catalysts typically operate under highpressure and high-temperature conditions, and these reactive environments may substantially influence the alloy surface composition. Theoretical studies of catalytic properties are often investigated on model systems where no account is taken for the possibility that the surface composition can be modified after the gas exposure. This is a serious drawback that may prevent reliable description of the catalyst reactivity that mainly depends on the configuration of the surface. Nowadays, modelling the equilibrium structure of metal surfaces and alloys in a reactive environment is still a barely studied subject and remains an extremely challenging task. Recent methodological advances and their applications, mainly on gold-based alloy systems, are presented and discussed in this brief overview.

First-Principles Study of Mo Segregation in MoNi(111): Effects of Chemisorbed Atomic Oxygen

“…The recent experimental and theoretical works focusing on the description of bimetallic and ternary, extended and nanosized, alloy surfaces under reactive gas phase environments were reviewed by Zafeiratos, et al [19] and by Guesmi [20]. On the theory side, Guesmi and co-workers had performed extensive first-principles calculations to investigate the transition metal segregation behaviors for the gold-based bimetallic systems in the presence of various gas adsorptions [11,12,21,22,23].…”

Alloying Behavior of Self‐Assembled Noble Metal Nanoparticles

“…In contrast, the formation of Pd shells was observed in several other experiments . The Pd segregation could be explained by its high affinity towards oxygen . Moreover, Mariscal et al predicted the formation of an Au–Pd alloy upon the collision of two monometallic clusters …”

“…[45][46][47] The Pd segregation could be explained by its high affinity towards oxygen. [43,46,48] Moreover, Mariscal et al predicted the formation of an Au-Pd alloy upon the collisiono ft wo monometallic clusters. [49] More information about the first coordination spheres of each metal in 1:1P t-Pd aerogelsw as gained by EXAFS measurements.…”

Stability of nanostructured silver-platinum alloys

“…the particle size, morphology and composition. This has become less problematic thanks to application of powerful theoretical methods [9,11,12].…”