Figure 19.

(A) (top) STM image of 0.04 ML of O/Au(110)-(1×2); (bottom) analysis of oxygen redistribution induced by 3 × 10^–10 Torr water at 170 K.⁴⁴² (B) CO₂ formation upon a CO titration experiment on Au(111) at 140 K. The Au(111) surface had been precovered with 0.11 ML ¹⁶O. In (B) 0.14 ML H₂¹⁸O were additionally adsorbed. Inset shows the total amount of CO₂ produced in each case.⁵⁵ (C) CO₂ intensity (m/z = 45 (red); m/z = 47 (blue)) during CO oxidation on Au(332) during a pulsed molecular beam experiment at 250 K for “dry” (left) and “wet” conditions (right). A constant flux of ¹³CO (p = 2.4 × 10^–6 mbar) and H₂¹⁸O (p = 5.1 × 10^–6 mbar) and pulses of oxygen atoms (duration 150 s; flux(¹⁶O) = 8 × 10¹² cm^–2s^–1) was applied. (A) Reproduced with permission from ref (442). Copyright 2018 Royal Society of Chemistry. (B) Reproduced in part with permission from ref (55). Copyright 2008 American Chemical Society. (C) Prepared by us from data in ref (435).