Thermal　catalytic　degradation　of　organic　pollutants　conducted　in　the　dark　at　room　temperature　under　atmospheric　pressure　without　the　need　of　external　chemicals　and　energy　sources　has　attracted　a　lot　of　attention　over　the　last　two　decades.　It　provides　unparalleled　advantages　over　other　advanced　oxidation　processes　(AOPs)　in　treating　domestic　and　industrial　contaminated　wastewater　from　the　viewpoint　of　energy/chemical　conservation　and　ease　of　operation.　Rich　knowledge　has　been　accumulated　in　terms　of　the　synthesis　and　application　of　thermal　catalysts　though　controversies　remain　regarding　their　underlying　mechanisms.　This　review　sheds　light　on　the　proposed　thermo-catalysis　mechanism　for　the　first　time　and　presents　the　development　of　thermal　catalysts　under　dark　ambient　conditions　with　a　focus　on　catalyst　materials,　catalytic　activity,　and　mechanism.　The　present　review　aims　to　provide　mechanistic　insights　into　the　rational　design　of　novel　and　efficient　catalysts,　and　their　underlying　mechanisms　as　well　as　the　emerging　challenges　and　perspectives　in　thermo-catalysis　under　dark　ambient　conditions　used　for　the　practical　and　efficient　treatment　of　contaminated　wastewater.　©　2019　Dalian　Institute　of　Chemical　Physics,　Chinese　Academy　of　Sciences