Reduction by Activated Carbon Does reduction by carbon itself occur when filtration is performed using activated carbon? Is it part of the central mechanisms involved in activated carbon filtration?
One of the specificities of all activated carbon, per my understanding, is it's large surface area, which allows it to be treated in a way or another and maximize the surface area on which the respective reaction occurs. Now, just as all activated carbon has a high surface area (with some variations), can it be said that all activated carbon acts as a highly potent reducer on some ions?
The only case I know of where activated carbon causes reduction at room temperature would be filtration of ozone, $\ce{O3}$. Even fluorine will not oxidize plain carbon:

Carbon is stable in a fluorine atmosphere up to about $\pu{400 ^\circ C}$ .

Oh, well perhaps dioxygen difluoride, $\ce{FOOF}$, could also oxidize carbon (or could be reduced by carbon, should you prefer a passive voice). Read Derek Lowe's Things I Won’t Work With: Dioxygen Difluoride, if you'd care to test that. Please let me know so that I could arrange to  be elsewhere.