Catalytic Urea Electrooxidation on Nickel-Metal Hydroxide Foams For Use
in A Simplified Dialysis Device
Abstract
Electrocatalytic urea removal is a promising technology for artificial
kidney dialysis and wastewater treatment. Urea electrooxidation was
studied on a variety of nickel electrocatalysts modified with Cr, Mo,
Mn, and Fe with varying electrochemically active surface and roughness.
Mass transfer limits were observed for urea oxidation at physiological
concentrations (10 mM). Urea oxidation kinetics were explored at higher
concentrations (200 mM), showing improved performance during
polarization, but lower currents per active site. A simplified dialysis
model was developed to examine the relationship of mass transfer
coefficients and extent of reaction on flowrate, composition, and pH of
the reacting stream. For a nickel hydroxide catalyst, the model shows
that a minimum electrode area of 1314 cm 2 is needed
for continuous operation. This research combines experimental data and a
computational dialysis model for a simplified continuous dialysis
system, highlighting the potential of these catalysts and paving the way
for future improvements.