Our operando monitoring reveals unambiguously an electrochemically driven restructuring into the catalytically active CoO2 species via the CoOOH intermediates in L-CoS for the OER. However, the exact role of all oxidized anionic components in the OER is still not completely clear from the operando XAS characterizations. This open question was finally elucidated by performing structural and electrochemical characterizations of Co-LDH reference in the presence of SO4 2-anions in the electrolyte for the OER (discussion and details in Figures ). Our results corroborate that the surface residual chalcogens are not the key to initiate the OER, since no OER enhancement took place in the Co-LDH + SO4 2-experiments. However, taking into account all complementary information from operando monitoring and electrochemical characterization, we propose that the presence of sulfur-related anions in the Cobased catalysts can initially trigger an underlying sulfuroxygen exchange reaction, which facilitates the structural flexibility for restructuring into the OER active Co 4+ species, thereby offering a better OER activity (discussion and details in Figure ). Furthermore, the results obtained from pH-dependent experiments and rotating ring-disk electrode characterization suggest that the ratedetermining step of the OER of L-CoS is limited by the generation of Co Ⅳ =O intermediates and the generation of O2 originates from the depronatation of OOH* intermediates (discussion and details in Figure ). To obtain in-depth insights into the kinetics of metal redox behaviours and their key role in tuning the O-O formation, we believe that time-revolved surface-sensitive spectroscopy coupled with electrochemical kinetic analysis approaches is essential.