Carbon　supports　with　a　low　ratio　of　micropore　volume　to　total　pore　volume　can　be　prepared　by　KOH　activation　of　thermally　modified　carbon.　KOH　treatment　of　carbons　in　nitrogen　led　to　the　creation　of　basic　sites　as　well　as　acidic　surface　groups,　whereas　KOH　treatment　in　air　resulted　in　more　acidic　groups.　Steam　treatment　quickly　increased　the　surface　area　and　pore　volume,　but　did　not　create　surface-reactive　groups.　The　increase　in　surface　areas,　micropores,　and　surface　functional　groups　of　carbon　supports　led　to　a　decrease　of　the　particle　sizes,　which　not　only　improved　the　ability　of　hydrogen　to　migrate　from　Ru　metal　to　the　remote　promoter　precursors,　but　also　increased　the　amount　of　adsorbed　hydrogen　and　nitrogen.　The　properties　of　carbon　combined　with　the　size　of　the　Ru　particles　affected　the　ammonia-synthesis　activity.　©　2013　WILEY-VCH　Verlag　GmbH　&　Co.