[Zurück]

P. Amann, B. Klötzer, D. Degerman, N. Köpfle, T. Götsch, P. Lömker, Ch. Rameshan, K. Ploner, D. Bikaljevic, H. Wang, M. Soldemo, M. Shipilin, C. Goodwin, J. Gladh, J. Stenlid, M. Börner, C. Schlueter, A. Nilsson:
"The state of zinc in methanol synthesis over a Zn/ZnO/Cu(211) model catalyst";
Science, 376 (2022), 376; S. 603 - 608.

The active chemical state of zinc (Zn) in a zinc-copper (Zn-Cu) catalyst during carbon dioxide/carbon
monoxide (CO 2/CO) hydrogenation has been debated to be Zn oxide (ZnO) nanoparticles, metallic Zn,
or a Zn-Cu surface alloy. We used x-ray photoelectron spectroscopy at 180 to 500 millibar to probe
the nature of Zn and reaction intermediates during CO2 /CO hydrogenation over Zn/ZnO/Cu(211),
where the temperature is sufficiently high for the reaction to rapidly turn over, thus creating an almost
adsorbate-free surface. Tuning of the grazing incidence angle makes it possible to achieve either
surface or bulk sensitivity. Hydrogenation of CO 2 gives preference to ZnO in the form of clusters or
nanoparticles, whereas in pure CO a surface Zn-Cu alloy becomes more prominent. The results reveal
a specific role of CO in the formation of the Zn-Cu surface alloy as an active phase that facilitates
efficient CO2 methanol synthesis

http://dx.doi.org/10.1126/science.abj7747