However, Li + suffers from greater CO 2 transport limitations and lower [Li + ] OHP due to its larger hydrated radius, and a higher barrier for cation transport to reaction plane, leading to a lower number of microenvironments (Figure ). The CO 2 adsorption rate for Li + is significantly lower, and it competes with the kinetically limited first PCET at lower applied potentials, leading to the peak being located at the lowest V RHE of the batch.