TY - JOUR
T1 - 1-Ethyl 3-methylimidazolium thiocyanate ionic liquid as corrosion inhibitor of API 5L X52 steel in H 2 SO 4 and HCl media
AU - Corrales-Luna, Mónica
AU - Le Manh, Tu
AU - Romero-Romo, Mario
AU - Palomar-Pardavé, Manuel
AU - Arce-Estrada, Elsa M.
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/6
Y1 - 2019/6
N2 - The corrosion inhibition behavior of 1-ethyl 3-methylimidazolium thiocyanate, (EMIM) + (SCN) − ionic liquid (IL), on API 5 L X52 steel immersed in 0.5 M H 2 SO 4 and 0.5 M HCl aqueous solutions were studied. The kinetic corrosion parameters were determined using a gravimetrical method and electrochemical tests (polarization curves, electrochemical impedance spectroscopy). The (EMIM) + (SCN) − exhibited good inhibition efficiency, IE, (82.9% and 77.4% for H 2 SO 4 (75 ppm) and HCl (100 ppm) solutions) properties in both solutions acting as a mixed-type inhibitor. In H 2 SO 4 the IE increased with increasing IL concentration and temperature, while in HCl IE decreased with the temperature increase. The IL adsorption mechanism followed the Langmuir isotherm, presenting a competition between the physical and chemical interactions. Surface analysis techniques (energy dispersive spectroscopy and X-ray photoelectron spectroscopy) indicate that the inhibitor formed a protective film on the steel surface, evidencing the adsorption of the cation (EMIM) + and the anion (SCN) − of the IL on the steel surface, which corroborates that both the (EMIM) + and the (SCN) − of IL interact with the substrate. The evaluation of interactions of (EMIM) + (SCN) − molecules with H 2 SO 4 and HCl in the presence of water on different surfaces of iron Fe and Fe 2 O 3 (110) plane was performed, using molecular dynamics to determine the inhibitor adsorption energies in both acid media. The simulation results are in close agreement with the experimental observations that the inhibition efficiency is better in H 2 SO 4 solution in comparison with that in HCl due to the higher adsorption energy values obtained in H 2 SO 4 medium.
AB - The corrosion inhibition behavior of 1-ethyl 3-methylimidazolium thiocyanate, (EMIM) + (SCN) − ionic liquid (IL), on API 5 L X52 steel immersed in 0.5 M H 2 SO 4 and 0.5 M HCl aqueous solutions were studied. The kinetic corrosion parameters were determined using a gravimetrical method and electrochemical tests (polarization curves, electrochemical impedance spectroscopy). The (EMIM) + (SCN) − exhibited good inhibition efficiency, IE, (82.9% and 77.4% for H 2 SO 4 (75 ppm) and HCl (100 ppm) solutions) properties in both solutions acting as a mixed-type inhibitor. In H 2 SO 4 the IE increased with increasing IL concentration and temperature, while in HCl IE decreased with the temperature increase. The IL adsorption mechanism followed the Langmuir isotherm, presenting a competition between the physical and chemical interactions. Surface analysis techniques (energy dispersive spectroscopy and X-ray photoelectron spectroscopy) indicate that the inhibitor formed a protective film on the steel surface, evidencing the adsorption of the cation (EMIM) + and the anion (SCN) − of the IL on the steel surface, which corroborates that both the (EMIM) + and the (SCN) − of IL interact with the substrate. The evaluation of interactions of (EMIM) + (SCN) − molecules with H 2 SO 4 and HCl in the presence of water on different surfaces of iron Fe and Fe 2 O 3 (110) plane was performed, using molecular dynamics to determine the inhibitor adsorption energies in both acid media. The simulation results are in close agreement with the experimental observations that the inhibition efficiency is better in H 2 SO 4 solution in comparison with that in HCl due to the higher adsorption energy values obtained in H 2 SO 4 medium.
KW - 1-Ethyl 3-methylimidazolium thiocyanate
KW - API 5L X52 steel
KW - Acid media
KW - Corrosion inhibition
KW - Ionic liquid
UR - http://www.scopus.com/inward/record.url?scp=85063616018&partnerID=8YFLogxK
U2 - 10.1016/j.corsci.2019.03.041
DO - 10.1016/j.corsci.2019.03.041
M3 - Artículo
SN - 0010-938X
VL - 153
SP - 85
EP - 99
JO - Corrosion Science
JF - Corrosion Science
ER -