English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

Formation of a 2D Meta-stable Oxide by Differential Oxidation of AgCu Alloys

MPS-Authors
/persons/resource/persons179553

Prieto,  Mauricio
Interface Science, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons213883

Tanase,  Liviu Cristian
Interface Science, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons229447

Gottlob,  Daniel M.
Interface Science, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons22076

Schmidt,  Thomas
Interface Science, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons22071

Schlögl,  Robert
Max-Planck Institute for Chemical Energy Conversion, Department of Heterogeneous Reactions;
Inorganic Chemistry, Fritz Haber Institute, Max Planck Society;

/persons/resource/persons135780

Jones,  Travis
Inorganic Chemistry, Fritz Haber Institute, Max Planck Society;

External Resource
No external resources are shared
Fulltext (public)

acsami.0c03963.pdf
(Publisher version), 9MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Schweinar, K., Beeg, S., Hartwig, C., Rajamathi, C. R., Kasian, O., Piccinin, S., et al. (2020). Formation of a 2D Meta-stable Oxide by Differential Oxidation of AgCu Alloys. ACS Applied Materials and Interfaces, 12(20), 23595-23605. doi:10.1021/acsami.0c03963.


Cite as: http://hdl.handle.net/21.11116/0000-0006-4C9B-7
Abstract
Metal alloy catalysts can develop complex surface structures when exposed to reactive atmospheres. The structures of the resulting surfaces have intricate relationships with a myriad of factors, such as the affinity of the individual alloying elements to the components of the gas atmosphere, and the bond strengths of the multitude of low-energy surface compounds that can be formed. Identifying the atomic structure of such surfaces is a prerequisite for establishing structure-property relationships, as well as for modeling such catalysts in ab initio calculations. Here we show that an alloy, consisting of an oxophilic metal (Cu) diluted into a noble metal (Ag), forms a meta-stable 2-dimensional oxide monolayer the more oxophilic metal, when the alloy is subjected to oxidative reaction conditions. The presence of this oxide is correlated with selectivity in the corresponding test reaction of ethylene epoxidation. In the present study, using a combination of in-situ, ex-situ and theoretical methods (NAP-XPS, XPEEM, LEED, and DFT) we determine the structure to be a 2-dimensional analogue of Cu2O, resembling a single lattice plane of Cu2O. The overlayer holds an pseudo-epitaxial relationship with the underlying noble metal. Spectroscopic evidence shows that the oxide’s electronic structure is qualitatively distinct from its 3-dimensional counterpart, and due to weak electronic coupling with the underlying noble metal, it exhibits metallic properties. These findings provide precise details of this peculiar structure, and valuable insights into how alloying can enhance catalytic properties.