pHtasemete

pHtasemete is a theoretical concept in chemistry and electrochemistry that refers to a proposed mechanism for local pH regulation at micro- and nanometer scales near catalytic interfaces. The term was coined in discussions of how proton transfer might operate independently of bulk solution pH to create a stabilized microenvironment during chemical reactions.

In the pHtasemete model, a surface- or pore-confined mediator cycles between protonated and deprotonated states. Through rapid proton exchange with the surrounding medium, this mediator can transiently donate or absorb protons, generating a localized pH gradient that persists even as the bulk pH changes. The effect would be most pronounced in confined geometries or under high surface activities where proton flux is large.

Empirical support for pHtasemete is not established. Some experiments report short-lived pH perturbations near active sites that cannot be fully explained by bulk buffering or known transport processes, while other studies attribute observations to measurement artifacts or conventional buffering. The concept remains controversial and is not widely adopted in standard practice.

If validated, pHtasemete could influence catalyst design, enzyme-inspired systems, and microfluidic devices by enabling more precise pH control at reaction sites, improving selectivity and efficiency in pH-sensitive processes.

See also: pH, buffer solution, proton sponge, proton-coupled electron transfer, electrochemical sensing.