Hydrogen Adsorption in Nanoporous Nickel(II) Phosphates

• Published in: Journal of the American Chemical Society Vol. 125; no. 5; pp. 1309 - 1312
• Main Authors: Forster, Paul M, Eckert, Juergen, Chang, Jong-San, Park, Sang-Eon, Férey, Gérard, Cheetham, Anthony K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 05.02.2003
• Subjects: Adsorption and desorption kinetics; evaporation and condensation; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid-fluid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Inorganic adsorbate; Adsorption site; Adsorption capacity; Transition elements Compounds; Inorganic adsorbent; Nickel phosphates; Thermally stimulated desorption; Experimental study; Physisorption; Neutron diffusion; Gas solid adsorption; Inelastic scattering; Gas solid interface; Adsorption structure; Hydrogen molecules
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja028341v

Hydrogen sorption in the nanoporous nickel phosphates VSB-1 and VSB-5 has been studied with a combination of BET, temperature programmed desorption (TPD), and inelastic neutron scattering (INS) measurements. H2 BET isotherms for VSB-1 are similar to those seen in nanoporous zeolites, while VSB-5 adsorbs substantially more hydrogen due to a steep initial uptake at low partial pressures. TPD data show that hydrogen interacts strongly with VSB-5, with desorption peaks at 109 and 149 K in a nitrogen flow, whereas the absence of similar peaks for VSB-1 suggests a weaker interaction. INS spectra of the rotational tunnel transition of the adsorbed H2 also reveal a strong interaction with the VSB-5 host. These data strongly suggest the existence of coordinatively unsaturated Ni2+ sites accessible to H2 molecules in the pores of VSB-5.