Q2. What is the eqn of a dc current?
At sufficiently high frequeitcies the second term in eqn. (10) will become infinitely small, so that apparently a “charge transfer resistance” R, remains.
Q3. What is the common Tafel slope?
In the, review given by Kuhn and Byrne [7] it can be seen that usually only one Tafel slope is reported, but a variety of values between 0.12 V (a = 0.5) to 0.03 V (a = 2j was found.
Q4. What slopes were obtained from the sweep experiments?
the slopes of the ln k, vs. E curves from the sweep experiments appear to be 11:s~ steep, especially at the lower current densities.
Q5. What is the reaction order of c*u+?
Depending on the reaction mechanism251and the extent of adsorption of the hydrogen atom, the reaction order in c*u+ can be second, first or zero order, but also in between these-values according to the ~‘u+ values in Table 1.
Q6. What is the value of the charge transfer resistance?
The impedance measurements were analyzed using the procedure developed in a separate paper [25] to obtain the value of the charge transfer resistance R,, as a function of dc potential.
Q7. What is the explanation for the phctogenerated atomic hydrogen?
the results for the phctogenerated atomic hydrogen appear to depend on the crystallographic orientation of the surface of the gold ejectrode [32] so another mechanism might be operative in this case.
Q8. How many times does the value of L be larger than?
As eqn. (12) is obeyed by their results down to 9 = 0, it is easily realized that for any possible third term, e.g. exp(lS+)/f., or exp(2@)/L,, the value of L, should be larger than ca. 30 ,times Lz.
Q9. What is the simplest way to determine the exchange current densities of gold?
Hz + site (R3’)The idea behind this scheme is to suppose the presence of “sites” (presumably foreign atoms) on the surface where H-atoms are adsorbed more strongly than at the gold atoms L;: zl that the recombination reaction promds at these sites preferably.