Title: Tuning the Kinetic Water Stability and Adsorption Interactions of Mg-MOF-74 by Partial Substitution with Co or Ni

Abstract

Varying amounts of Co and Ni were substituted into the metal–organic framework Mg-MOF-74 via a one-pot solvothermal reaction, and the effects of these substitutions on CO₂ adsorption and kinetic water stability properties were examined. Based on elemental analyses, Co and Ni are more favorably incorporated into the MOF-74 framework from solution than Mg. In addition, reaction temperature more strongly impacts the final metal composition in these mixed-metal (MM) MOF-74 structures than does the reaction solvent composition. Single-component CO₂ adsorption isotherms were measured for the MM-MOF-74 systems at 5, 25, and 45 °C, and isosteric heats of adsorption were calculated. These results suggest that CO₂ adsorption properties can be adjusted by partial metal substitution. Water adsorption isotherms were also measured for the MM-MOF-74 samples, with powder X-ray diffraction patterns and Brunauer–Emmett–Teller surface areas measured both before and after water exposure. Results show that Mg-MOF-74 can gain partial kinetic water stability by the incorporation of Ni²⁺ or Co²⁺ metal ions that are less vulnerable to hydrolysis than Mg²⁺. Finally, of particular note, Mg–Ni-MM-MOF-74 shows a significant increase in water stability when incorporating as little as 16 mol % Ni into the Mg-MOF-74 structure.

Authors:

Jiao, Yang ^[1]; Morelock, Cody R. ^[1]; Burtch, Nicholas C. ^[1]; Mounfield, William P. ^[1]; Hungerford, Julian T. ^[1]; Walton, Krista S. ^[1]

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+ Show Author Affiliations

1. Georgia Inst. of Technology, Atlanta, GA (United States)

Publication Date:

Fri Nov 20 00:00:00 EST 2015

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Understanding and Control of Acid Gas-induced Evolution of Materials for Energy (UNCAGE-ME)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1370923

Grant/Contract Number:  

SC0012577

Resource Type:

Accepted Manuscript

Journal Name:

Industrial and Engineering Chemistry Research

Additional Journal Information:

Journal Volume: 54; Journal Issue: 49; Related Information: UNCAGE-ME partners with Georgia Institute of Technology (lead); Lehigh University; Oak Ridge National Laboratory; University of Alabama; University of Florida; University of Wisconsin; Washington University in St. Louis; Journal ID: ISSN 0888-5885

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; catalysis (heterogeneous); defects; membrane; carbon capture; materials and chemistry by design; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)