Direct　oxidation　of　methane　into　value-added　liquid　chemicalsisa　promising　route　for　wide　applications.　However,　the　efficient　conversionof　methane　with　high　selectivity　under　mild　conditions　is　still　challenging.Herein,　the　catalysts　of　rhodium　dispersed　on　ZSM-5　were　synthesizedfor　the　methane　conversion　utilizing　molecular　O-2　as　theoxidant　together　with　CO　and　H2O　under　a　total　pressureof　40　bar　at　＜100　&　DEG;C.　Moreover,　the　conversion　of　methaneand　the　selectivity　of　formic　acid　could　be　improved　by　increasingacidity　over　the　Rh/ZSM-5　catalysts.　Promoted　by　H+,　theactivities　of　methane　oxidation　can　reach　3.56　mol(HCOOH)/mol(Rh)/h　and　23.96　mol(HCOOH)/mol(Rh)/h　at　50　and　90　&　DEG;C　over　the　5.0Rh/H-ZSM-5　catalyst,　and　theselectivity　of　HCOOH　of　98.48%　to　all　organic　oxygenates　can　be　acquiredat　90　&　DEG;C.　Dramatically,　the　activation　of　the　C-H　bondcan　even　happen　at　room　temperature.　Electron　paramagnetic　resonanceresults　showed　that　acidity　can　promote　the　generation　of　&　BULL;OHwith　CO,　H2O,　and　O-2　as　the　reactants,　resultingin　high　catalytic　activity　under　mild　conditions.