Defining contribution of micropore size to hydrogen physisorption behaviors: A new approach based on DFT pore volumes

In recent years, nanoporous materials with high specific surface areas and porosity have been developed to meet the commercial demands of hydrogen storage systems. Subnanometer micropores of less than 1 nm are known for their excellent performances in hydrogen physisorption, but their exact contribution and temperature-dependent adsorption performance are still ambiguous. In this work, we have prepared microporous carbons using Ketjenblack with various micropore size portions via chemical activation. In addition, we propose a new density functional theory (DFT) pore volume-based model to determine the contribution of pore size to gas adsorption. The values of the contribution factor (k) derived from the proposed model indicate the effect on the physical adsorption by pore size and are indicated to be inversely proportional to temperature. The proposed model and k values can be used for an important method for ambiguous physical adsorption studies.