Table 3.

Parameters obtained via EEC for the EIS data for al immersed in 0.5 M H₂SO₄ without and with Vanillin as corrosion inhibitor.

Cinh (mM)	Rs (Ω cm2)	CPEdl (×10− 5, F cm− 2)	n dl	Rct (Ω cm2)	L (H cm2)	RL (Ω cm2)	CPEinh (×10− 5, F cm− 2)	n inh	Rinh (Ω cm2)	Rp (Ω cm2)	%IE
25 °C
0	9.17	1.94	0.9	702	53.51	73.94	2.29 × 10− 8	0.4	17.93	803.05
2	4.78	9.20	0.9	1200	229.5	334.82	1.06 × 10− 5	0.8	1626.00	3165.58	75
4	4.86	1.57	0.9	713.8	66.71	106.91	1.06 × 10− 4	0.8	228.00	1053.56	24
6	4.75	1.10	0.9	970.4	102.6	173.60	9.01 × 10− 5	0.8	224.40	1373.15	42
8	8.16	1.14	0.9	751.9	78.47	130.30	1.06 × 10− 4	0.6	401.70	1292.06	38
10	62.15	1.46	0.9	323	266.1	291.13	5.87 × 10− 7	0.8	1867.00	2543.25	68
40 °C
0	2.70	1.49	0.9	25.93	1.446	11.24	1.87 × 10− 6	0.9	131.50	171.374
2	3.64	5.58	0.9	1307	42.77	353.8	2.72 × 10− 7	0.4	788.10	2452.55	93
4	2.55	1.30	0.9	11.69	4.25	27.77	3.99 × 10− 8	0.4	249.70	291.75	41
6	2.47	1.36	0.9	23	13.9	169.5	1.34 × 10− 7	0.4	745.50	940.47	82
8	2.95	1.33	0.9	23	3.927	18.14	1.74 × 10− 7	0.3	288.50	332.60	48
10	2.51	1.36	0.9	40.8	12.82	54.04	6.55 × 10− 9	0.3	444.40	541.75	68
60 °C
0	7.47	1.47	0.9	102.60	1.31	15.34	1.46 × 10− 2	0.4	39.74	165.15
2	3.03	1.02	0.9	60.22	2.81	17.93	2.37 × 10− 5	0.7	207.6	288.78	43
4	10.37	1.77	0.9	198.02	14.3	27.58	2.45 × 10− 2	0.4	23.45	259.42	36
6	2.36	1.93	0.9	188.70	1.60	16.57	5.27 × 10− 2	0.4	52.33	259.96	36
8	2.97	1.85	0.9	89.41	3.32	8.02	9.58 × 10− 2	0.4	22.76	123.17	–
10	2.14	7.92	0.9	16.00	3.25	43.74	2.67 × 10− 7	0.9	228.3	290.18	43