Promoted ammonium salt-protected activated carbon sorbent particles for removal of mercury from gas streams. A method of separating mercury from a mercury-containing gas stream includes contacting a mercury-containing gas stream with an activated carbon sorbent including promoted ammonium salt-protected activated carbon sorbent particles, to form a mercury-sorbent composition. The method also includes separating at least some of the mercury-sorbent composition from the mercury-containing gas stream, to give a separated gas.