Distribution of geometrical current density inside a flow-by porous electrode: Effect of electrode parameters and electrochemical reactions

Abstract

The effect of the difference between the equilibrium potentials of the target and side reactions, the solution flow rate, and specific surface area of porous electrode (PE) on the distribution of the geometrical current density along the solution flow ig(y) at various average current densities is studied by the method of mathematical modeling. It is found that the largest range of the variation of ig(y) (the exponential decrease along the solution flow) is typical for the conditions that provide the limiting current mode of the target reaction on the entire PE surface in the absence of simultaneous hydrogen evolution. All changes in the operation conditions, which reduce the uniformity of the distribution of the current inside PE along the X axis and hamper reaching the limiting current mode (for example, a decrease in the equilibrium potential difference, an increase in the flow rate or specific surface area of PE) lead to more uniform distribution of ig(y).