Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

Hierarchically porous carbons (HPCs) with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis, environmental treatment, and energy storage and conversion. Herein, we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and wastes. During the carbonization, zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in carbons. The prepared HPCs exhibit high specific surface areas (up to 2432 m(2) g(-1)), large pore volumes (up to 4.30 cm3 g(-1)), and broad pore size distributions. Moreover, the zinc salts can be recovered and recycled, supporting the sustainable production of HPCs on large scale. The prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction. (c) 2023 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, a method for synthesizing hierarchically porous carbons (HPCs) with multimodal pores was reported by directly carbonizing diverse biomass and waste materials with the assistance of zinc salts. The prepared HPCs exhibited high surface areas, large pore volumes, and broad pore size distributions. The zinc salts used in the synthesis process could be recovered and recycled, supporting the sustainable production of HPCs on a large scale. The HPCs-supported catalysts showed promising electrocatalytic performance for the oxygen reduction reaction.