![]() The processing of the experimental data was carried out. We propose a simple one-dimensional non-stationary model of the transport of diluted species during the anodic oxidation of paracetamol using REM to describe the above effects. This work aims to study the processes underlying the reduction in the efficiency of anodic oxidation, and in particular the formation of gas bubbles and the recharge of the REM pore surface at a current density exceeding the limiting kinetic value. The main problem with REM is the formation of fouling and gas bubbles in the pores, which leads to a decrease in the efficiency of the process because the hydraulic resistance increases and the electrochemically active surface is shielded. The use of reactive electrochemical membranes (REM) in flow-through mode during the anodic oxidation of organic compounds makes it possible to overcome the limitations of plate anodes: in the case of REM, the area of the electrochemically active surface is several orders of magnitude larger, and the delivery of organic compounds to the reaction zone is controlled by convective flow rather than diffusion. The work points out the feasibility and problems of zinc electrowinning under high current density situation, which could provide necessary reference the electrowinning field. The increase of current density on the electrolytic cell and electrode plate is the direct cause of accelerating zinc deposition and aggravating anodic corrosion. Finally, the distribution of secondary current density in the electrolytic cell was simulated by the method of computational fluid dynamics. In addition, the corrosion behavior of Pb-Ag anode at high current density was studied, which suggest that Pb-Ag anode displays higher surface roughness and lower oxygen evolution overpotential at high current density with the main corrosion phase of β-PbO2. The XRD analysis of the zinc plates at different current densities revealed that high current densities change the zinc growth preferential orientation, leading to poor surface quality. The percentage of hydrogen evolution at current density 800 A/m² increased by 3.3% compared to 500 A/m², and the current efficiency decreased by 3.06%. The results suggest that the increase of current density increases the proportion of hydrogen evolution at the cathode and thus decreases the current efficiency. In this work, the effects of high current density (500 A/m², 600 A/m², 700 A/m², 800 A/m²) on zinc electrodeposition as well as the anodic corrosion behavior of lead silver alloy were investigated. The twinned-textured growth morphology can be considered as an index of high particulate entrainment in a cathode for quality control purposes using optical metallography. The formation of random nodules on the copper cathodes can be related to the synergistic effect of particulates and the disturbance in the electrolyte velocity. In these conditions, the random tips created by the topographic transitions require a relatively lower potential and therefore the current localized on these areas may develop nodules by either 3D nucleation or re-twinning field-oriented growth. At constant current density, the higher electrolyte velocity increases the potential required for electrodeposition by increasing the inhibition intensity (the boundary layer of inhibitors at the deposition front decreases and more catalyzation sites can be masked/inhibited). The nodulation is mostly associated with the cathodes placed near the electrolyte outlet in the tank house, where the electrolyte is considered likely to be at a significantly higher velocity. In the case of high inhibition intensity, grain size contraction may occur which increases the possibility of formation of field-oriented growth and nodulation. Depositing particulates on the deposition front may cause topographic transitions from the favorable valley-based growth to the less favorable peak-based growth by hindering the lateral growth via masking the re-entrant catalyzing corners, leading to final nodulation of the cathode. A descriptive model for the twin-textured growth morphology of electro-refined copper cathodes is proposed, taking into account the effect of suspended particulates as an integral part of industrial electro-refining baths on the electrocatalytic behavior of the deposition front. ![]()
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