Corrections to ``Chemisorbed Oxygen Structures on the Rhodium (110) Surface''

The effect of surface oxygen on hydrocarbon reactions catalyzed by platinum crystal surfaces with variable kink concentrations

“…The crystals were exposed to 02 at 800°C, cooled to ~SO°C to obtain an Auger spectrum, and there- peaks with hydrogen chemisorbed at terraces and steps, respectively. from the step to terrace atom concentration ratios As expected,A the (Tp ~140°C)/(Tp ~22S0C) peak area ratios at saturation were ~ 3:1 and 2:1 for Pt (12,9,8) As illustrated in Fig.8, TNm refers to the maximum in the time dependent reactivity, TN(t), that was observed 3-15 minutes after starting the reaction. This reaction, as well as the others we investigated, self-poisoned over a period of 0.5-10 hours, depending on the pressure, surface structure ( Fig.Sa), temperature ( Fig.8b) and…”

“…On Pt(l0,8,7) and Pt(l2, 9,8), with 0.25 ~ 05l0/Pt237~0.4, a less intense , (2x 2) -0 s t ruc tu re samet imes coex i s ted wi th the (/3x/3}0 structure.…”

“…The growth of ordered multilayers was detected for Pt (12,9,8) and Pt(654) following extensive oxygen exposure at SOOO( (~103L).…”

“…Alternatively, -9 an isolable 2" cryotrapped diffusion pump Cbase P ~8xlO torr) To begin a reaction, hydrogen and hydrocarbon were intro- and Pt (12,9,8) when the 0SlO/Pt 237 Auger peak-topeak height ratio was 0.20-0.25. As shown in Fig.2a for Pt (12,9,8) the predominant pattern \\'as due to a (l3xl3) -R300-0 structure on from the oxygen surface structure the (Ill) terraces. On Pt(10,8,7) the diffraction spotsAwere diffraction spots due to the occasionally split in the same direction as theAsubstrate _, indicating that the oxygen layer was coherent over several terraces.…”

“…

\We have investigated the oxygen and hydrogen chemisorption ' ' "properties and catalytic activi ties of the (12,9,8), (10, 8, 7), (654) and (321) platinum crystal surfaces which have (111) terraces, St~ong chemiso~ption of hydrogen at kink sites was correlated with the greater resistance to self-poisoning of kinked surfaces as compared to PtClll) and stepped Pt(SS7).

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