Acid-base transport model of interfacial reactions for dynamic pH
response quantification and regulation
Abstract
The dynamic pH response resulting from acid-base transport of
interfacial reactions greatly influences the kinetic performance and
process mechanism, but its theoretical foundation is lacked. Herein, a
generalized acid-base transport model is established owing to the
success in deriving buffer transport equations and is experimentally
through the relationships of buffer transport limiting current versus
solution pH and buffer concentration (CB). The relationships bring forth
the parameter determination methods of buffers with the superiority of
facile survey of practical parameter values. Based on model
calculations, the dynamic pH response is drawn as a j‒pH diagram to show
the buffer transport law in the full pH range, highlighting the
rate-limiting effect. The buffer operation principles are graphically
presented as CB‒ΔpH diagrams to aid economic buffer applications. This
study has laid the foundation for quantification and regulation of
dynamic pH response and is of wide interest to the chemistry
encompassing interfacial processes.