TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The catalyst is prepared by:(A) preparing graphite oxide comprising dispersing graphite powder in concentrated sulfuric acid, potassium thiosulfate solution and phosphorus pentoxide mixed solution at mass ratio of 9:1:1, oil bath heating to 60-80 degrees C to carry out reflux while stirring for 3-6 hours, cooling to room temperature, placing into ice-water bath, dropping deionized water, stirring overnight, filtering through 0.1-0.5 mu m Teflon membrane filter to remove excess acid, and drying to room temperature to obtain pre-oxidized graphite; dispersing in concentrated sulfuric acid at molar ratio of 1:3, adding potassium permanganate at mass ratio of 1:5 while maintaining ice water bath temperature to not greater than 20 degrees C, stirring to 20-50 degrees C for 1-5 hours, dropping deionized water for 1-5 hours, and adding hydrogen peroxide solution; and filtering, washing with hydrochloric acid and water at volume ratio of 1:8-15, washing with deionized water, drying to ambient temperature, adding into dialysis bag, dialyzing for 1-2 weeks, removing metal ions, filtering, and drying to ambient temperature;(B) preparing phenolic resin prepolymer comprising dispersing phenol in 37 wt.% formaldehyde aqueous solution, adding sodium hydroxide, stirring to 50-70 degrees C for 1-2 hours, adding polypropylene glycol and polymer F127 dispersed in deionized water, and reacting to 50-100 degrees C through oil bath for 10-30 hours; and(C) preparing molybdenum-doped mesoporous carbon-graphene complex comprising ultrasonically dispersing obtained graphite oxide in deionized water at mass ratio of 2:1, adding obtained phenolic resin prepolymer and ammonium molybdate, ultrasonically agitating to obtain homogeneous solution, transferring into autoclave, and reacting to 120-160 degrees C for 10-30 hours; naturally cooling to room temperature, washing with deionized water and ethanol, filtering, and drying solid powder; and calcining to 600-900 degrees C for 1-5 hours under argon atmosphere.