▎ 摘　　要

NOVELTY - Catalyst coated with nitrogen-doped graphene quantum dots (N-GQDs) comprises 0.1-20 wt.% vanadium oxide, 0.1-20 wt.% tungsten trioxide, titanium dioxide (remaining amount), and 0.1-5 wt.% nitrogen-doped graphene quantum dots which is coated on the surface, and selective catalyst reduction (SCR) efficiency is improved in the temperature range of 160-300° C. USE - The catalyst is useful for improving selective catalyst reduction efficiency (claimed). ADVANTAGE - The catalyst prevents the formation of metal sulfate on the catalyst surface by coating the catalyst surface with N-GQDs having gas-selective adsorption characteristics, when N-GQDs are coated on the catalyst surface, nitric oxide adsorption, is easily made and the nitric oxide adsorption amount on the catalyst surface increases, shows a denitrification efficiency of 93% at 200° C, shows a tendency of 32% increase compared to the catalyst without N-GQD coating, when 300 ppm of sulfur dioxide was included in the reaction gas, the denitrification efficiency of the reference catalyst material decreased by 12.7%, reduces the denitrification efficiency by 1%, and confirms that the sulfur dioxide poisoning resistance was greatly improved. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing catalyst coated with N-GQDs on the surface for improving SCR efficiency, comprising synthesizing N-GQD, vanadium oxide precursor and tungsten trioxide precursor, synthesizing vanadium oxide-tungsten trioxide/titanium dioxide catalyst using titanium dioxide precursor, and synthesizing N-GQDs-vanadium oxide-tungsten trioxide/titanium dioxide catalyst by coating the synthesized catalyst with N-doped graphene quantum dot aqueous solution.