Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

Table 1

Corrosion parameters and polarization resistance of copper electrode in 0.5 M PO⁴³⁻ solutions in the absence or presence of different concentrations of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF₄) of pH 2 and 4 at 20°C.

Inhibitor	pH	Concentration inhibitor (mM)	−𝐸corr (mV)	𝑗corr (μA cm^−2)	− 𝑏𝑐 (mV dec^−1)	𝑏𝑎 (mV dec^−1)	𝑅𝑃 (Ω cm^2)
Blank		0.0	60	29.0	300	75	898
4MBPBF4		1.0	64	16.0	280	70	1519
	2	5.0	79	13.2	277	67	1846
		10.0	94	10.5	275	65	2174
		25.0	99	6.5	228	63	5158
		50.0	104	2.4	180	60	8141
Blank		0.0	60	20.0	240	160	2084
4MBPBF4		1.0	200	10.0	175	190	3955
	4	5.0	240	8.0	148	291	5987
		10.0	278	5.0	120	400	8016
		25.0	273	3.4	115	410	13478
		50.0	268	1.2	110	420	27824