A series of three-dimensional (3D)-interconnected hierarchical porous carbons (HPCs) were prepared through a "leavening" strategy. alpha-Cellulose and NaHCO3 were used as a raw material and foaming agent, respectively, to support copper catalysts (Cu/HPC) for dimethyl carbonate (DMC) synthesis by the oxidative carbonylation of methanol. The calcination temperature had a significant influence on the textural properties of the HPC and the catalytic performance of the Cu/HPC. The catalyst calcined at 900 degrees C exhibited the highest catalytic activity with a DMC space-time yield of 2018 mg/(g h). The characterization results indicated that the outstanding catalytic activity was related to the highest dispersion of copper species and to a high content of surface Cu-0 species, which can be attributed mainly to the enhanced anchoring effect of abundant micro- and mesopores of a 3D-interconnected network. In addition, the well-developed 3D-interconnected hierarchical porous structure provided a rapid and efficient channel for reactant and product transport and migration, which enhanced the catalytic performance. This work expands the potential application range of HPC materials and presents a novel procedure to prepare catalysts for DMC synthesis.