Table 3. EXAFS data fitting results of y% Na–2.16% Pt/FeO _x samples ^a .

Samples	Shell	N	R (Å)	σ 2 × 102 (Å2)	ΔE 0 (eV)	r-factor (%)
Pt foil	Pt–Pt	12.0	2.76	0.41	6.1	0.42
PtO2	Pt–O	6.0	2.00	0.41	7.2	0.56
	Pt–Pt	6.0	3.08	0.99	2.1
2.16% Pt/FeO x	Pt–O	1.2	1.99	0.30	4.7	0.91
	Pt–Fe	1.1	2.54	0.54	4.7
	Pt–Pt	0.7	2.68	0.54	4.7
5.03% Na-2.16% Pt/FeO x	Pt–O	2.5	2.01	0.18	9.6	0.92
	Pt–Fe	0.4	2.54	0.46	9.6
	Pt–Pt	0.5	2.75	0.46	9.6
	Pt–Na	1.0	2.95	0.73	9.6

^a N, the coordination number for the absorber–backscatterer pair. R, the average absorber–backscatterer distance. σ ², the Debye–Waller factor. ΔE ₀, the inner potential correction. The accuracies of the above parameters were estimated as N, ±20%; R, ±1%; σ ², ±20%; ΔE _0, ±20%. The data ranges used for data fitting in k-space (Δk) and R-space (ΔR) are 3.0–10.7 Å^–1 and 1.2–3.5 Å, respectively.