a		b		c
1.5 mbar, H2, 220oC		1.5 mbar, H2 /H2O=3/1, 220oC		5 mbar, H2 /CO=95/5, 220oC

Environmental TEM (ETEM) images of a methanol synthesis catalyst consisting of Cu nanocrystals supported on ZnO.
Below each image the corresponding Wulff construction is displayed, which shows the 3D shape of the Cu nanocrystals.
The images were acquired in situ with the sample at 220 °C, and exposed to the following gas compositions:
(a) H2 at 1.5 mbar, (b) a mixture of 75% H2 and 25% H2O at 1.5 mbar, and (c) a mixture of 95% H2 and 5% CO at 5 mbar.