▎ 摘　　要

NOVELTY - Graphene-coated catalyst comprises glucose as a carbon source, ferric nitrate as an iron source, and potassium as an auxiliary agent, and forms a graphene-coated core-shell structure of iron carbide-coated iron carbide through pyrolysis and carbonization processes at high temperatures. The content of iron is 10-40 wt.%, and potassium adjuvant is 0.5-5 wt.%. The preparation method includes sequentially dissolving ferric nitrate and glucose in deionized water, the mass ratio of ferric nitrate to glucose is 1:5-1:1 respectively, adding potassium nitrate as an auxiliary agent, and continuously stirring to form a light yellow solution, heating to 75-85 degrees to evaporate the solvent, and drying overnight in an oven at 60 degrees C to obtain a brown-black viscous foamy substance, which is the iron-glucose precursor, calcining the iron-glucose precursor at 700-900 degrees C for 1-3 hours in a flowing nitrogen atmosphere, the heating rate used is 1-3 degrees C/minute. USE - The catalyst is useful for encapsulating iron carbide particles and synthesizing gas to prepare low-carbon olefin. ADVANTAGE - The catalyst has good catalyst stability and strong electronic effect, and high reaction activity.