▎ 摘　　要

NOVELTY - Preparing vicinal diol by catalytic hydrogenolysis of lignocellulose, involves converting lignocellulosic vitamin raw material into ortho-diol by performing hydrogenation reaction at 180-220℃ for 2-4 hours, with aqueous solution of liquid acid as solvent, in presence of magnetic metal catalyst wrapped in graphene-like carbon shell, under hydrogen pressure 5.5 millipascals (MPa). The graphene-like carbon shell layer coated metal catalyst is prepared by mixing metal salt with organic acid and deionized water, stirring for 6 hours at 80-100℃, raising temperature to 100℃, keeping for 12 hours, to form powder sample at 600-800℃, then calcining for 3 hours, under nitrogen atmosphere. The molar ratio of metal salt to organic acid, used, is 1: 1. The metal ion salt is chloride, nitrate and/or sulfate ion salt of VIIIB group transition metal. The liquid acid used, is hydrochloric acid, sulfuric acid or phosphoric acid. The organic acid used is citric acid. USE - Method is used for preparing vicinal diol by catalytic hydrogenolysis of lignocellulose. ADVANTAGE - The method is a simple process which involves mild conditions, for preparing vicinal dihydric alcohol. The method enables to covert cellulose, efficiently into ortho- dihydric alcohol, by using inexpensive catalyst which has enhanced catalyst activity, without need for further hydrogenation reduction. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of metal catalyst coated by graphene carbon shell layer.