Amorphous　metal　oxides　have　aroused　extensive　research　interest　in　heterogeneous　catalysis　owing　to　their　high　surface　area　and　rich　surface　defects.　In　this　work,　we　synthesized　a　series　of　non-crystalline　derivatives　of　Mn-BTC-BM　MOF　using　a　mechanochemical　approach　for　NH3-selective　catalytic　reduction　(SCR).　The　thermal　decomposition　of　Mn-BTC-BM　at　400gases　yielded　Mn　(II,　III)　oxide　(Mn-BTC-BM-400)　with　retained　non-crystalline　characteristics,　which　exhibited　a　smaller　grain　size　and　lower　Mn-O　bond　energy　than　derivatives　obtained　through　hydrothermal　methods　and　other　temperatures.　This　results　in　increased　surface　defects　and　acidic　sites,　promoting　the　release　of　lattice　oxygen　and　leading　to　optimal　low-temperature　NH3-SCR　activity.　The　Mn-BTC-BM-400　achieved　an　impressive　90　%　conversion　rate　for　NO　at　170　℃,　and　exhibited　the　lowest　apparent　activation　energy　(Ea=18　kJ/mol)　among　the　six　catalysts.　This　study　presents　a　simple　synthesis　approach　for　non-crystalline　MnOx　catalysts,　with　mechanochemical　synthesis　offering　promising　improvements　in　catalytic　performance.　©　2023