Effect of palladium loaded activated carbons on hydrogen storage

Pd-loaded high surface area activated carbon (BAC-Pd) was produced from bamboo by carbonization and activation using potassium hydroxide with subsequent loading of palladium. The palladium loaded onto BACs appears to exist more in micropores. The Pd compounds exist mainly as amorphous PdCl2 with Pd (0) structures in the whole surface of BAC-Pd. The hydrogen adsorption capability of BAC-Pd at 0.1 MPa and room temperature was evaluated for hydrogen storage. The amount of adsorbed hydrogen on BAC-Pd was the maximum among three Pd-loaded activated carbons because the physical properties and the Pd content are the highest among them. According to the effect of Pd content, the amounts of adsorbed hydrogen on BAC-Pd increased linearly as the Pd content increased, and the BET surface area of BAC-Pd decreased. BAC, which had the highest Pd contents in micropores, exhibited excellent adsorption ability for hydrogen at 298 K and 0.1 MPa. The amounts of chemisorbed hydrogen of BAC-Pd increased along with the increase in Pd content. Furthermore, the amount of adsorbed hydrogen of BAC-Pd is expected to increase in conditions with pressure higher than 0.1 MPa.