Table 2. Full Quantitative EDX Analysis of La₂NiO₄, La₂Ni_0.9Cu_0.1O₄, and La_1.8Ba_0.2Ni_0.9Cu_0.1O₄ in the Initial and Spent Catalyst State^a.

DRM	sample	La-L at.-%	Ni–K at.-%	O–K at.-%	Cu–K at.-%	Ba-L at.-%	total at.-%
before	LaNiO3	17.87 ± 1.61	15.61 ± 2.82	66.51 ± 3.21	-	-	100
after	LaNiO3	23.31 ± 3.41	18.42 ± 3.83	58.26 ± 6.33	-	-	100
before	La2NiO4	30.09 ± 4.73	15.16 ± 2.76	54.74 ± 7.29	-	-	100
after	La2NiO4	21.64 ± 3.18	11.59 ± 2.23	66.75 ± 5.27	-	-	100
before	La2Ni0.9Cu0.1O4	27.36 ± 2.07	14.42 ± 4.49	56.63 ± 5.13	1.57 ± 1.26	-	100
after	La2Ni0.9Cu0.1O4	21.84 ± 2.19	10.7 ± 1.42	65.26 ± 3.56	2.19 ± 0.43	-	100
before	La1.8Ba0.2Ni0.9Cu0.1O4	24.66 ± 3.25	12.07 ± 2.53	60.6 ± 4.29	2.66 ± 0.66	0b	100
after	La1.8Ba0.2Ni0.9Cu0.1O4	23.34 ± 4.02	12.47 ± 2.48	62.36 ± 6.67	1.80 ± 0.30	0b	100

^aFor the sake of comparability, the EDX data of the archetypical LaNiO₃ system is also shown.

^bBa could not be quantified directly using this method due to the strong overlap of the Ba-L edge with that of La-L. This means that La-L is slightly overestimated, but still within the error margin of the method.