skip to main content

Title: Rapid design of top-performing metal-organic frameworks with qualitative representations of building blocks

Data-driven materials design often encounters challenges where systems possess qualitative (categorical) information. Specifically, representing Metal-organic frameworks (MOFs) through different building blocks poses a challenge for designers to incorporate qualitative information into design optimization, and leads to a combinatorial challenge, with large number of MOFs that could be explored. In this work, we integrated Latent Variable Gaussian Process (LVGP) and Multi-Objective Batch-Bayesian Optimization (MOBBO) to identify top-performing MOFs adaptively, autonomously, and efficiently. We showcased that our method (i) requires no specific physical descriptors and only uses building blocks that construct the MOFs for global optimization through qualitative representations, (ii) is application and property independent, and (iii) provides an interpretable model of building blocks with physical justification. By searching only ~1% of the design space, LVGP-MOBBO identified all MOFs on the Pareto front and 97% of the 50 top-performing designs for the CO2working capacity and CO2/N2selectivity properties.

more » « less
Award ID(s):
1818574 1729452
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
npj Computational Materials
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Metal-organic frameworks (MOFs) exhibit great promise for CO2capture. However, finding the best performing materials poses computational and experimental grand challenges in view of the vast chemical space of potential building blocks. Here, we introduce GHP-MOFassemble, a generative artificial intelligence (AI), high performance framework for the rational and accelerated design of MOFs with high CO2adsorption capacity and synthesizable linkers. GHP-MOFassemble generates novel linkers, assembled with one of three pre-selected metal nodes (Cu paddlewheel, Zn paddlewheel, Zn tetramer) into MOFs in a primitive cubic topology. GHP-MOFassemble screens and validates AI-generated MOFs for uniqueness, synthesizability, structural validity, uses molecular dynamics simulations to study their stability and chemical consistency, and crystal graph neural networks and Grand Canonical Monte Carlo simulations to quantify their CO2adsorption capacities. We present the top six AI-generated MOFs with CO2capacities greater than 2m mol g−1, i.e., higher than 96.9% of structures in the hypothetical MOF dataset.

    more » « less
  2. Abstract

    Solution‐processable semiconducting 2D nanoplates and 1D nanorods are attractive building blocks for diverse technologies, including thermoelectrics, optoelectronics, and electronics. However, transforming colloidal nanoparticles into high‐performance and flexible devices remains a challenge. For example, flexible films prepared by solution‐processed semiconducting nanocrystals are typically plagued by poor thermoelectric and electrical transport properties. Here, a highly scalable 3D conformal additive printing approach to directly convert solution‐processed 2D nanoplates and 1D nanorods into high‐performing flexible devices is reported. The flexible films printed using Sb2Te3nanoplates and subsequently sintered at 400 °C demonstrate exceptional thermoelectric power factor of 1.5 mW m−1K−2over a wide temperature range (350–550 K). By synergistically combining Sb2Te32D nanoplates with Te 1D nanorods, the power factor of the flexible film reaches an unprecedented maximum value of 2.2 mW m−1K−2at 500 K, which is significantly higher than the best reported values for p‐type flexible thermoelectric films. A fully printed flexible generator device exhibits a competitive electrical power density of 7.65 mW cm−2with a reasonably small temperature difference of 60 K. The versatile printing method for directly transforming nanoscale building blocks into functional devices paves the way for developing not only flexible energy harvesters but also a broad range of flexible/wearable electronics and sensors.

    more » « less
  3. Functional porous metal–organic frameworks (MOFs) have been explored for a number of potential applications in catalysis, chemical sensing, water capture, gas storage, and separation. MOFs are among the most promising candidates to address challenges facing our society related to energy and environment, but the successful implementation of functional porous MOF materials are contingent on their stability; therefore, the rational design of stable MOFs plays an important role towards the development of functional porous MOFs. In this Focus article, we summarize progress in the rational design and synthesis of stable MOFs with controllable pores and functionalities. The implementation of reticular chemistry allows for the rational top-down design of stable porous MOFs with targeted topological networks and pore structures from the pre-selected building blocks. We highlight the reticular synthesis and applications of stable MOFs: (1) MOFs based on high valent metal ions ( e.g. , Al 3+ , Cr 3+ , Fe 3+ , Ti 4+ and Zr 4+ ) and carboxylate ligands; (2) MOFs based on low valent metal ions ( e.g. , Ni 2+ , Cu 2+ , and Zn 2+ ) and azolate linkers. We envision that the synthetic strategies, including modulated synthesis and post-synthetic modification, can potentially be extended to other more complex systems like metal-phosphonate framework materials. 
    more » « less
  4. Abstract

    A tetra(carboxylated) PCP pincer ligand has been synthesized as a building block for porous coordination polymers (PCPs). The air‐ and moisture‐stable PCP metalloligands are rigid tetratopic linkers that are geometrically akin to ligands used in the synthesis of robust metal–organic frameworks (MOFs). Here, the design principle is demonstrated by cyclometalation with PdIICl and subsequent use of the metalloligand to prepare a crystalline 3D MOF by direct reaction with CoIIions and structural resolution by single crystal X‐ray diffraction. The Pd−Cl groups inside the pores are accessible to post‐synthetic modifications that facilitate chemical reactions previously unobserved in MOFs: a Pd−CH3activated material undergoes rapid insertion of CO2gas to give Pd−OC(O)CH3at 1 atm and 298 K. However, since the material is highly selective for the adsorption of CO2over CO, a Pd−N3modified version resists CO insertion under the same conditions.

    more » « less
  5. Abstract

    Hybridization of metal–organic frameworks (MOFs) and polymers into composites yields materials that display the exceptional properties of MOFs with the robustness of polymers. However, the realization of MOF–polymer composites requires efficient dispersion and interactions of MOF particles with polymer matrices, which remains a significant challenge. Herein, we report a simple, scalable, bench‐top approach to covalently tethered nylon–MOF polymer composite materials through an interfacial polymerization technique. The copolymerization of a modified UiO‐66‐NH2MOF with a growing polyamide fiber (PA‐66) during an interfacial polymerization gave hybrid materials with up to around 29 weight percent MOF. The covalent hybrid material demonstrated nearly an order of magnitude higher catalytic activity for the breakdown of a chemical warfare simulant (dimethyl‐4‐nitrophenyl phosphate, DMNP) compared to MOFs that are non‐covalently, physically entrapped in nylon, thus highlighting the importance of MOF–polymer hybridization.

    more » « less