Reconstruction of Clean and Oxygen-Covered Pt(110) Surfaces

Abstract

We studied clean and oxygen-covered surfaces of unreconstructed and reconstructed Pt(110) by density functional theory (DFT) calculations and used these data in thermodynamic considerations to establish the stabilities of these surfaces as a function of the oxygen surface coverage. The clean Pt(110) prefers to reconstruct into a (1 × n) missing-row structure with n = 2−4. The surface free energies of the three reconstructed surfaces are very similar within the accuracy of our calculations. Upon oxygen adsorption, the c(2 × 2) with 0.5 monolayer (ML) coverage on the unreconstructed surface is equally stable as the 0.5 ML coverage on the Pt( 110)-(1 × 2) reconstructed surface. There is no clear transition between (1 × 1) and (1 × 2). With increasing oxygen pressure, the fully oxygen-covered (1 ML) Pt( 110)-(1 × 2) becomes the most stable structure. We assume that this structure is relevant in the onset of the formation of bulk Pt-oxide. Compared to Au, we found that the Pt( 110)-(1 × 2) surface is very stable even under very positive electro potential, and the (1 × 3) structure is not stabilized by impurities (e.g., oxygen).

The quantum mechanics derived atomistic mechanism underlying the acceleration of catalytic CO oxidation on Pt(110) by surface acoustic waves

“…In this case the O 2 molecule binds with an adsorption energy of 0.72 eV, and goes through a saddle point with an energy barrier of 0.54 eV to form O-adatoms at two nearest-neighbor sites, as illustrated schematically in the left-hand-side, middle and right-hand-side, respectively, of Figure 2f for a (2x2) unit cell at 0.5 ML O-coverage. In contrast, in the absence of two adjacent vacant sites the probability of O 2 dissociation is negligible,23 in agreement with experiment 19. …”

“…We anticipate that our DFT results as reported below are in general consistent with both experiment and previous theoretical results. 20,23 However, one important difference we find with respect to previous computational studies is for the Eley-Rideal (ER) mechanism (the process in which a CO molecule hits a 1 ML-O-covered reconstructed Pt(110) surface and picks up an O adatom thus producing CO 2 ). To investigate this process in detail, we carried out the following calculations:…”

High-pressure operando STM studies giving insight in CO oxidation and NO reduction over Pt(110)

“…In this surface oxide, the O-atom-induced stress leads to the ejection of Pt atoms in a highly ordered manner, so that a Pt(1 1 0)-(12x2)-22O structure is adopted [24]. However, DFT combined with ab initio thermodynamics predicts that this surface oxide is not stable under reaction conditions [25,26].…”

Analytical results for the dynamics of parabolic level-crossing model

“…Suominen derived analytical approximations for the final state populations [26], and applied the results to the dynamics of cold atoms in magnetic traps [27]. In the same period, Zhu and Nakamura derived an exact formula for the scattering matrices in terms of a convergent infinite series, in which the coefficients satisfy a five-term recursion relation [28][29][30][31][32]. Nakamura and co-workers applied the results to laser assisted surface ion neutralization [33] and the laser-controlled photochromism in functional molecules [34].…”