While surface roughness is an obvious factor, this is not what is exactly asked. Rather, periodic variation of exchange current density (of an electrode) with solution chemistry (of electrolyte) and crystal structure (of the metallic electrode) is asked, if any of these exist.
The rate of electron transfer between an electrode and a redox center in solution is the main factor on which exchange current density depends on. I doubt that it can be predicted. It's always a good idea to read textbooks before asking any question.
Muhammad Bilal " lower Tafel slope." If I comment your answer I would be banned for using inappropriate wording"
I believe the exchange current density is at "zero" overpotential. Tafel equation relates current density to some over potential but it does not offer any insights about exchange current density when overpotential is zero.
Yurii V Geletii out of curiosity, would chrono-amperometry be useful here? The idea there is to provide a periodic modulation of the over-potential and monitor the response current decay while the overpotential is zero?
The Tafel plot is the dependence of the overpotential versus logarithm of the rate of an electrochemical reaction (current density). If you don't describe the reaction, how can you determine overpotential? The Tafel plot might be a linear function in a certain range of overpotential. Extrapolation to zero overpotential gives the exchange current. The exchange current density depends on the rate of electron transfer between an electrode and a redox center. The Tafel slope can be interpreted applying the theory behind this equation. Therefore, I don't think that there is any sense to discuss this ill formulated question and the naive answer.
Daniyal Kiani When I wrote my comments I've not read yet your answer. You are right and I recommended your answer
Muhammad Bilal The exchange current density is NOT a descriptor of the catalytic activity, but a descriptor of the electron transfer rate between an electrode and the redox center. "If you are using a specific electrode/electrolyte and know the rate of reaction, you may predict it" What is "it"? If "it" is the catalytic activity (define what is this), then you can't predict it. " the higher will be the exchange current density at lower overpotentials." The exchange current density is measured at zero overpotential." "lower Tafel slope" The Tafel slope is measured in the kinetically controlled region.
Daniyal Kiani "would chrono-amperometry be useful here?" Possibly, but I'm not sure. There is no theory of such technique. The contribution of the capacitor current might be too high.
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