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The electrochemical performances of deposited MnO2 on lead alloy anode by pulse current (PC) and direct current (DC) electrodeposition in manganese sulfate solution were investigated by performing measurements of galvanostatic polarization, cyclic voltammetry (CV), and Tafel tests. The composition and morphology of MnO2 were observed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The anode deposited with MnO2 layers by PC electrodeposition presented a lower anodic potential of 60 mV and more uniform potential oscillating attractor with fractal dimension of 1.0337 compared with those of DC electrodeposition. In addition, MnO2 layers exhibited excellent corrosion resistance because less intermediate oxide Mn­(III) appeared in anode deposits. Furthermore, the cathodic current efficiency improved by 3.11∼3.77% and energy consumption decreased by 5.30∼8.17% after galvanostatic electrolysis for 2∼8 h by using PC instead of DC for manganese metal electrodeposition. As an external control method, PC electrodeposition not only regulated the structure and surface morphology of MnO2 but also affected the anode electrochemical behaviors and cathode manganese metal deposition. Electrochemical oscillations and other characteristics of anode reaction described in this study could inspire future work on promoting the whole electrowinning process.

A novel supramolecular inclusion complex was prepared with cationic β-cyclodextrin and organic phosphoric acid. The inclusion action was investigated by UV−vis spectroscopy, and the cationic β-cyclodextrin inclusion complex was structurally evidenced by 1 H and 31 P NMR and FT-IR. With linear expansion tests, it was found that the novel inclusion complex possessed excellent clay stability. FT-IR, single-factor, and response surface method analyses showed that the inclusion complex acid system could not only retard acid−rock reaction but also intelligently regulate the acid−rock reaction rate to ensure a sufficient amount of acid to react with high-temperature oil-bearing sandstone reservoir in the progress of acid stimulation. On the basis of the core flood tests, an interaction mechanism was suggested that the inclusion complex acid system may open up for a new possibility to exhibit greater acidizing performance in high clay content, high-temperature, and low-permeability oil reservoirs, which contributes to improving core permeability and enhancing oil recovery.