Inhibition of copper corrosion in cooling seawater under flowing conditions by novel pyrophosphate

The inhibition of copper corrosion in cooling seawater by novel pyrophosphate SrNiP₂O₇ (SNP) was investigated under flowing conditions using mass-loss and electrochemical methods. The surface morphology was characterized by SEM coupled with EDX spectra. Comparable results show that SNP acts as a mixed-type inhibitor with predominantly cathodic effectiveness, suppressing the corrosive process by physical adsorption on the copper surface. The highest inhibition efficiency obtained from mass-loss, polarization and EIS measurements are 92.7%, 94.8% and 97.1%, respectively, at 120 mg L^-1 of SNP. The influence of increasing temperature on SNP inhibitor efficiency has been studied, and the activation energy has been calculated. Surface morphology observations evidenced the formation of a protective SNP film over the metal surface.