Defect engineered clay-rich media with enhanced hydrogen uptakes

In this study, various chemical treatments were performed on clay-rich media to investigate their effects on hydrogen adsorption performance. We unequivocally demonstrated that acid-treated samples exhibited significant structural changes compared with those treated with alkali solutions. Gas adsorption isotherms and powder X-ray diffraction analyses clearly revealed that the acid treatment of clayey materials not only increased their surface area, but also enhanced hydrogen sorption uptake, increased interstratification, and reduced particle size. Most importantly, we succeeded in rationalizing the improvement in hydrogen uptake by sequentially applying purification, followed by acid treatment.