Table 1.

Average domain sizes for calcined samples (before reduction) prepared by impregnation (determined by the Scherrer equation).

Sample	Phase	hkl	2·θ (°)	t (nm)	Phase	hkl	2·θ (°)	t (nm)
Ni/Al2O3	Al2O3	4-4-2	66.867	5.0
Ni/CeO2	CeO2	1-1-1	28.743	58.3	NiO	2-0-0	43.466	19.6
Ni/La2O3	La2O3	1-0-0	26.366	5.5
Ni/MgO	MgO	2-0-0	42.782	15.1
Ni/ZrO2	ZrO2	1-1-1	28.115	29.2	NiO	2-0-0	43.218	18.9