Impact of Various Acids and Bases on the Voltammetric Response of Platinum Group Metal Oxides

Table 1

Drift of the OCP (E versus RHE) of a RuO₂ electrode in various acids and bases at 25°C in the course of several days. For comparison: negative decadic logarithm of the dissociation constants of acids () and bases () from [12]. Theoretical potential of the reversible hydrogen electrode: V RHE = 0.059 pH (25°C).

Solution	pH (calculated)	pK (25°C)	Day 1 (E/mV)	Day 2 (E/mV)	Day 3 (E/mV)
1 M H2SO4	0.11	−3	920	923	920
1 M HCl	0.13	−7	815	697	850
1 M H3PO4	1.08	+2.13	866	889	864
1 M HNO3	0.13	−1.37	844	806	942
1 M NaOH	13.8	−1.1	702	710	912
1 M KOH	13.8	−0.56	846	972	902