Evaluation of corrosion mitigation properties of pyridinium-based ionic liquids on carbon steel in 15% HCl under the hydrodynamic condition: Experimental, surface, and computational approaches

Abstract

The corrosion process severely damages the carbon steel during the acidization. The present investigation described the corrosion inhibition application of two ionic liquids: 1-Butylpyridinium chloride (BPC) and 1-Butylpyridinium hexafluorophospate (BPH), for the protection of carbon steel in 15 % HCl under the hydrodynamic condition at 1500 rpm. The estimated results obtained by weight loss support the inhibitive performance of BPs are 90.0 % (BPC) and 72.5 % (BPH). The EIS results point out the rising values of Rct with the increasing amount of BPs and approach the highest value of 262.4 Ω cm2 (BPC) and 125.4 Ω cm2 (BPH). The PDP reveals the anodic nature of BPs inhibitive action. The Dubinine Radushkevich (d-RIM) adsorption isotherm model provides accurate fitting estimated data. The negative values of ΔHoads represent the exothermic nature of adsorption. The contact angle value is less (26.4°) for BPs free steel sample. However, a significant increase occurs in the contact angle values upon adding BPC (84.9°) and BPH (67.8°). The SEM, optical profilometry, contact angle, and XPS confirmed the presence of an adsorptive layer of BPs. DFT further suggests the better inhibitive performance of BPC than BPH.