Hydrogen Storage with Spectroscopic Identification of Chemisorption Sites in Cu-tdpat via Spillover from a Pt/activated Carbon Catalyst
Abstract
Hydrogen spillover to the Cu-TDPAT (TDPAT = 2,4,6-tris(3,5-dicarboxylphe-nylamino)-1,3,5-triazine) metal-organic framework is probed with adsorption measurements, ex situ characterization techniques, and density functional theory (DFT) calculations. At 1 bar and 300 K, hydrogen chemisorption to Pt/AC/Cu-TDPAT exceeds that expected for physisorption by 8-fold, which is attributable to both catalyst insertion and the creation of structural defects. Hydrogenation of (a) the Cu-O-C bond of the Cu paddlewheel, (b) the sp2 N heterocycle, and (c) the secondary amine is demonstrated with ex situ spectroscopy. Exothermic (with respect to H2) hydrogenation at the Cu-O-C bond of the paddlewheel is substantiated by DFT. However, hydrogenated Cu-O-C is metastable, as evidence for dissociation is found at higher temperature (i.e., 473 K H2). DFT calculations demonstrate hydrogenation of the N groups may occur exothermically only for a charged ligand, suggestive that defects may contribute to hydrogen chemisorption. At high pressure, slow adsorption rates and material instability render the material unsuitable for practical hydrogen storage applications.
Recommended Citation
C. Y. Wang et al., "Hydrogen Storage with Spectroscopic Identification of Chemisorption Sites in Cu-tdpat via Spillover from a Pt/activated Carbon Catalyst," Journal of Physical Chemistry C, vol. 118, no. 46, pp. 26750 - 26763, American Chemical Society (ACS), Oct 2014.
The definitive version is available at https://doi.org/10.1021/jp507395p
Department(s)
Chemical and Biochemical Engineering
Sponsor(s)
United States. Department of Energy.Office of Energy Efficiency and Renewable Energy
Keywords and Phrases
Adsorption; Catalysts; Chemisorption; Crystalline materials; Defects; Density functional theory; High pressure engineering; Hydrogen; Hydrogenation; Organometallics; Platinum; Adsorption measurement; Chemisorption sites; Hydrogen chemisorption; Hydrogen spill overs; Material instability; Metal organic framework; Spectroscopic identification; Structural defect; Hydrogen storage
International Standard Serial Number (ISSN)
1932-7447
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2014 American Chemical Society (ACS), All rights reserved.
Publication Date
01 Oct 2014
Comments
This work was supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy program, Award DEFG36-08GO18139. The computational work was supported through a Marie Curie International Incoming Fellowship (A.D.L.) and a Marie Curie International Reintegration Fellowship (G.P.).