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The mixed-metal strategy, by which a MOF framework with two different metal nodes was prepared, was utilized with MOF-74 for potential adsorption chiller applications. The Ni salt precursor was partially replaced during synthesis with the relatively inexpensive Zn salt. The bimetallic MOF-74 containing only a fraction of Ni was shown to provide efficient H2O adsorption performance, while utilizing the more inexpensive Zn salt thus significantly mitigated the material costs of industrial scale synthesis/applications. [ABSTRACT FROM AUTHOR]

Designing zeolites with tunable physicochemical properties can substantially impact their performance in commercial applications, such as adsorption, separations, catalysis, and drug delivery. Zeolite synthesis typically requires an organic structure-directing agent to produce crystals with specific pore topology. Attempts to remove organics from syntheses to achieve commercially viable methods of preparing zeolites often lead to the formation of impurities. Herein, we present organic-free syntheses of two polymorphs of the small-pore zeolite P (GIS), P1 and P2. Using a combination of adsorption measurements and density functional theory calculations, we show that GIS polymorphs are selective adsorbents for H2O relative to other light gases (e.g., H2, N2, CO2). Our findings refute prior theoretical studies postulating that GIS-type zeolites are excellent materials for CO2 separation/sequestration. We also show that P2 is significantly more thermally stable than P1, which broadens the operating conditions for GIS-type zeolites in commercial applications and opens new avenues for exploring their potential use in processes such as catalysis. [ABSTRACT FROM AUTHOR]

Zeolite HOU-2 (LTA type) is prepared with the highest silica content (Si/Al = 2.1) reported for Na-LTA zeolites without the use of an organic structure-directing agent. The rational design of Si-rich zeolites has the potential to improve their thermal stability for applications in catalysis, gas storage, and selective separations. [ABSTRACT FROM AUTHOR]