▎ 摘　　要

NOVELTY - Preparing catalyst comprises dispersing sulfonated graphene into water, adding a metal salt solution of palladium (II) ion or ruthenium (III) ion to it, adding a reducing agent to obtain palladium or ruthenium nanoparticles-sulfonated graphene catalyst. USE - The catalyst is useful for catalyzing meso-lactide to produce D, L-lactide. ADVANTAGE - The method: immobilizes palladium or ruthenium particles; improves the stability of the catalyst; increases the polarity of the graphene surface; promotes the adsorption of the reactant on the surface of the catalyst; and improves the reaction efficiency. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for : (1) catalyst; and (2) producing D, L-lactide by catalytic internal-racemic lactide comprising using the catalyst for catalyzing m-lactide to react, and producing D, L-lactide.