▎ 摘　　要

NOVELTY - Composite catalyst comprises porous three-dimensional reduced graphene oxide (3D-rGO) and MIL-101 (Cr) which is uniformly dispersed on the internal folds of three-dimensional reduced graphene oxide (3D-rGO). The mass ratio of MIL-101 (Cr) and 3D-rGO is 1:(1-3). The composite catalyst as a whole has a microporous structure. USE - The composite catalyst is useful for degrading and producing small molecular acid by straw (claimed). ADVANTAGE - The catalyst: has high catalytic effect; degrades cellulose in the straw into small molecular acid; utilizes waste resource; has higher selectivity, milder catalytic conditions and better catalytic efficiency; and produces less by-products. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing composite catalyst, comprising (i) preparing MIL-101(Cr)-3D-rGO composite by in situ synthesis of MIL-101 (Cr) on the internal pleats of 3D-rGO; and (ii) carrying out calcination activation of MIL-101(Cr)-3D-rGO composite; and #catalytic degradation of straw and straw extract microcrystalline cellulose to produce small molecular acid, comprising adding composite catalyst into an alkaline solution of cellulose, and degrading catalytically at 50-200 degrees C, where mass-to-volume ratio of the composite catalyst and alkaline solution of cellulose is: 0.1 g: 8 ml and the concentration of cellulose in the alkali solution of cellulose is 0.06 g/ml.