In　this　paper,　red　mud　(RM),　a　solid　waste　with　high　alkalinity　generated　by　the　alumina　production　industry,　was　modified　using　three　different　acids.　The　catalytic　efficiency　of　HNO3-MRM　was　the　best,　and　the　T10,　T50,　and　T90　were　280　℃,　325　℃,　and　361　℃,　respectively.　The　CO2　selectivity　of　HNO3-MRM　was　better　than　those　of　HCl-MRM　and　H2SO4-MRM.　Further,　the　HNO3-MRM　catalyst　maintained　high　stability　at　420　℃.　This　good　catalytic　performance　of　HNO3-MRM　is　related　to　its　high　specific　surface　area,　Fe3+　content,　surface　adsorbed　oxygen　content,　and　surface　acidic　sites.　The　reaction　rate　linearly　increases　with　the　number　of　surface　acidic　sites　on　the　catalyst,　indicating　that　surface　acidity　is　an　important　factor　affecting　the　catalytic　activity　of　toluene.　H2SO4　solution　forms　calcium　sulfate　with　Ca2+　in　the　RM,　resulting　in　a　lower　catalytic　activity　for　H2SO4-MRM.　Fe2O3,　Al2O3,　and　SiO2　were　the　main　components　of　HNO3-MRM.　Fe2O3　was　the　active　component　of　the　catalyst,　which　played　the　role　of　the　catalytic　oxidation　of　toluene.　Al2O3　and　SiO2　were　used　as　catalyst　carriers.　Moreover,　the　catalytic　mechanism　of　toluene　oxidation　over　the　HNO3-MRM　catalyst　was　studied.　The　catalytic　oxidation　of　toluene　on　HNO3-MRM　catalysts　may　have　two　simultaneous　reaction　paths.　The　first　reaction　path　would　be　toluene　→　species　benzyl→　benzaldehyde→　benzoic　acid→　heptaldehyde→　CO2　and　H2O.　The　second　reaction　path　would　be　toluene　→　benzene　→phenol　→　maleic　acid　→CO2　and　H2O.　©　2023　Elsevier　Ltd