The values of the rate constants for the reactions ( ), ( ) and ( ) can be found in the SI. The bulk values of the concentrations of the solution species: H + , OH -,HCO - 3 , CO 2 , CO and K + for a 0.1 M KHCO 3 solution saturated with CO 2 are assumed to be constant and are calculated by solving the transient rate equations for reactions ( ), ( ) and ( ) combined with the Sechenov equation (see SI for details).