Communication pubs.acs.org/JACS
Engineering of Pore Geometry for Ultrahigh Capacity Methane Storage in Mesoporous Metal−Organic Frameworks Cong-Cong Liang,†,‡ Zhao-Lin Shi,†,‡ Chun-Ting He,§,‡ Jing Tan,† Hu-Die Zhou,† Hao-Long Zhou,† Yongjin Lee,† and Yue-Biao Zhang*,† †
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China School of Chemistry, Sun Yat-Sen University, Guangzhou 510275, China
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S Supporting Information *
UMCM-1,10a MOF-20510b (aka DUT-610c), and MUF-7a10d (Scheme 1).
ABSTRACT: Mesoporous Zn4O(−COO)6-based metal− organic frameworks (MOFs), including UMCM-1, MOF-205, MUF-7a, and the newly synthesized MOFs, termed ST-1, ST-2, ST-3, and ST-4 (ST = ShanghaiTech University), have been systematically investigated for ultrahigh capacity methane storage. Exceptionally, ST-2 was found to have the highest deliverable capacity of 289 cm3STP/cm3 (567 mg/g) at 298 K and 5−200 bar, which surpasses all previously reported records held by porous materials. We illustrate that the fine-tuned mesoporosity is critical in further improving the deliverable capacities at ultrahigh pressure.
Scheme 1. Syntheses of Mesoporous Zn4O(−COO)6-Based MOFs by Mixing Tritopic Linkers with Ditopic Linkers to Make Previously Reported UMCM-1, MOF-205, MUF-7a, and the New MOFs Reported in This Work
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remendous efforts have been made to design superior porous materials for on-board methane storage to cut off CO2 emission from vehicles, an immediate solution for mitigating climate change.1,2 Integrating both inorganic clusters and organic struts, metal−organic frameworks (MOFs) are known for their diverse topologies, which codes for specific pore hierarchy, diverse pore geometries, and spatial arrangements of adsorption sites.3 As such, MOF structures offer exclusive opportunities for the manipulation of both host−guest interactions as well as guest−guest arrangements to boost the methane uptake at 298 K and relative lower pressure (e.g., 35 bar).1,4 Recently, prominent microporous MOFs, such as HKUST-1,5a MOF-5,2a,5b UTSA-76,5c MOF-520,5d Co(BDP),5e Al-soc-MOF-1,5f MAF-38,5g MOF-905,5h and MFM-115a5i were found to have high deliverable volumetric capacities when considering the retention of minimal inlet pressure (5 bar) with increased operational pressure (e.g., 65 or 80 bar).6 However, ultrahigh deliverable capacities, necessary for enabling applications in heavy-duty or long-haul vehicles, have yet to come to fruition.7 Herein, we targeted ultraporous MOFs possessing narrow mesopores (pore sizes < 4 nm), which have demonstrated drastically improved methane storage capacity at pressures up to 250 bar, conditions that are industrially viable for the adsorbed natural gas (ANG) applications.8 In order to maximize the deliverable capacity, the unusable methane uptake (
