Atomic-Scale View of the Oxidation and Reduction of Supported Ultrathin FeO Islands

TY - JOUR

T1 - Atomic-Scale View of the Oxidation and Reduction of Supported Ultrathin FeO Islands

AU - Li, Yijia

AU - Adamsen, Kræn C.

AU - Lammich, Lutz

AU - Lauritsen, Jeppe V.

AU - Wendt, Stefan

PY - 2019/10

Y1 - 2019/10

N2 - By means of scanning tunneling microscopy (STM) measurements, we studied in situ the oxidation and reduction of FeO bilayer islands on Au(111) by oxygen (O2) and hydrogen (H2), respectively. The FeO islands respond very dynamically toward O2, with the coordinatively unsaturated ferrous (CUF) sites at the island edges being essential for O2 dissociation and O atom incorporation. An STM movie obtained during oxidation reveals how further O2 molecules can dissociate after the consumption of all initially existing CUF sites through the formation of new CUF sites. In contrast, we found that H2 molecules only dissociate when vibrationally excited through the ion gauge and only at the basal plane of FeO islands, implying that the CUF sites are not relevant for H2 dissociation. Our STM results reveal how excess O atoms are incorporated and released in O2 and H2 and thus shed light onto the stability of inverse catalysts during a catalyzed reaction.

AB - By means of scanning tunneling microscopy (STM) measurements, we studied in situ the oxidation and reduction of FeO bilayer islands on Au(111) by oxygen (O2) and hydrogen (H2), respectively. The FeO islands respond very dynamically toward O2, with the coordinatively unsaturated ferrous (CUF) sites at the island edges being essential for O2 dissociation and O atom incorporation. An STM movie obtained during oxidation reveals how further O2 molecules can dissociate after the consumption of all initially existing CUF sites through the formation of new CUF sites. In contrast, we found that H2 molecules only dissociate when vibrationally excited through the ion gauge and only at the basal plane of FeO islands, implying that the CUF sites are not relevant for H2 dissociation. Our STM results reveal how excess O atoms are incorporated and released in O2 and H2 and thus shed light onto the stability of inverse catalysts during a catalyzed reaction.

KW - catalysis

KW - dissociation

KW - H

KW - iron oxide

KW - O adatom dislocation lines

KW - O

KW - STM movies

UR - http://www.scopus.com/inward/record.url?scp=85072914623&partnerID=8YFLogxK

U2 - 10.1021/acsnano.9b05470

DO - 10.1021/acsnano.9b05470

M3 - Journal article

C2 - 31513376

AN - SCOPUS:85072914623

SN - 1936-0851

VL - 13

SP - 11632

EP - 11641

JO - ACS Nano

JF - ACS Nano

IS - 10

ER -