Heterometallic Aluminum Metal-Organic Frameworks

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Nature utilizes charge-complementary metal ions like M(II) and Al(III) in materials such as spinel and layered double hydroxides.
• Heterometallic combinations, specifically Mg-Al, have been notably absent in metal-organic frameworks (MOFs).

Purpose of the Study:

• To report the synthesis of novel heterometallic Al-MOFs containing M(II)/Al(III) trimeric clusters.
• To investigate the gas adsorption and separation properties of these newly synthesized MOFs.

Main Methods:

• Cooperative crystallization of M(II) and Al(III) using M(II) chlorides and aluminum lactate.
• Synthesis of pore-space-partitioned MOFs with partitioned acs topology.
• Gas uptake and selectivity measurements at 298 K and 1 bar.
• Experimental breakthrough experiments for gas mixture separations.

Main Results:

• Successfully synthesized heterometallic Al-MOFs with M(II)/Al(III) trimeric clusters (M = Mg, Mn, Co, Ni).
• Achieved fast crystallization kinetics (approx. 3 hours) and tunable porosity.
• Exhibited high gas uptakes: 112 cm³/g for CO2, 176 cm³/g for C2H2, 156 cm³/g for C2H4, and 163 cm³/g for C2H6.
• Demonstrated high selectivity for C2H2/CO2 (up to 8.5) and C2H2/C2H4 (up to 10.8).

Conclusions:

• The synergistic effect of M(II) chlorides and aluminum lactate enables efficient cooperative crystallization.
• The synthesized heterometallic Al-MOFs offer promising applications in gas storage and selective gas separations.
• These MOFs present a new class of materials for addressing challenges in carbon capture and hydrocarbon separations.