H2 Adsorption on Cu(I)–SSZ-13

We report H2 adsorption capacities reaching 0.05 wt % at 303 K and at 1 atm H2 pressure on solid-state CuCl-exchanged [Al]-SSZ-13 and [B]-SSZ-13 zeolites. Differential heat of H2 adsorption is found in the range between 16 and 48 kJ mol H2–1 on Cu­(I)-SSZ-13 at 323 K and isosteric heat of adsorption is found between 20 and 55 kJ mol H2–1 on Cu­(I)-[B]-SSZ-13 at temperatures between 293 and 323 K. Strong interactions between H2 and the copper cations in Cu­(I)-SSZ-13 are evidenced using Rietveld refinements of neutron powder diffraction patterns revealing Cu–deuterium (D2) distances of 2.3(2) and 2.41(1) Å. A temperature-dependent Cu­(I) migrationaway from the six-membered ring (6MR) and eight-membered ring (8MR)is related to the high adsorption capacities of the samples at 303 K. At 10 K, access to Cu­(I) at 6MR is sterically hindered by framework oxygen atoms (Cu–Oframework distance of 2.196(5) Å), rationalizing the low H2 adsorption capacities of Cu­(I)-SSZ-13 samples as compared to Na-SSZ-13 at 77 K.