Pyrazole ionic liquid corrosion inhibitor for magnesium alloy: Synthesis, performances and theoretical explore

A novelty ionic liquid 1-ethyl-2-benzyl bis (trifluoromethylsulfonyl) amides ([EBPz][NTf 2 ]) was synthesized and characterized. The corrosion protection of [EBPz][NTf 2 ] on AZ91D magnesium alloy in 0.05 wt% NaCl solution was studied. • The ionic liquids [EBPz][NTf 2 ] is novelty and can protect AZ91D magnesium alloy well. • Under the influence of temperature, the inhibition efficiency of [EBPz][NTf 2 ] did not decrease obviously. • A combination of experimental and theoretical methods was used in the research. A novelty ionic liquid 2-benzyl-1-ethyl-1 H -pyrazolium bis (trifluoromethyl- sulfonyl) amides ([EBPz][NTf 2 ]) was synthesized and characterized, which is environmentally friendly and has high corrosion inhibition efficiency for AZ91D Mg alloy in 0.05 wt% NaCl solution. The corrosion properties of [EBPz][NTf 2 ] was studied by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDS), scanning electron microscope-energy dispersive spectrometer (SEM-EDX), atomic force microscope (AFM) and x-ray diffraction (XRD) analysis. The results show that the corrosion inhibition efficiency of [EBPz][NTf 2 ] reaches 91.4% when the concentration is 200 ppm..X-ray photoelectron spectroscopy (XPS) combined with the density functional theory (DFT) calculation was used to investigate the corrosion inhibition mechanism.