▎ 摘　　要

NOVELTY - A composite catalyst comprises modified sepiolite, and reduced graphene oxide (rGO), copper and europium loaded on the modified sepiolite. The modified sepiolite is prepared by sodium-modifying sepiolite with sodium carbonate. USE - Composite catalyst is used in catalytic removal of formaldehyde (claimed). ADVANTAGE - The composite catalyst is economically prepared with excellent catalytic elimination effect and high stability, by simple process, and can effectively eliminate high-concentration formaldehyde (500-3000 ppm) at low temperature of 30-90℃. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: preparation of the composite catalyst, which involves (S1) adding sodium carbonate to purified sepiolite, stirring for 4-8 hours at 60-80℃, aging at room temperature for 30-50 hours, washing, filtering, and drying at 80-120℃ for 24 hours to obtain modified sepiolite, (S2) dispersing single-layer graphene oxide powder in deionized water, ultrasonically processing for 6-10 hours to obtain single-layer graphene oxide suspension, adding copper nitrate and europium nitrate to deionized water, uniformly mixing to obtain mixed solution of copper nitrate and europium nitrate, adding single-layer graphene oxide suspension and polyvinyl alcohol to the mixed solution of copper nitrate and europium nitrate under condition of -10℃ to 0℃ in ice water bath, stirring for 1-2 hours, injecting sodium borohydride solution to form dark brown suspension, continuously stirring for 1-2 hours to obtain copper-europium/reduced graphene oxide (Cu-Eu/rGO) suspension, and (S3), adding the modified sepiolite to copper-europium/reduced graphene oxide suspension, stirring for 6-10 hours, washing, drying, and calcining; and use of the composite catalyst in catalytic removal of formaldehyde. The concentration of formaldehyde is 500-3000 ppm.