Snyder Benjamin E R, Turkiewicz Ari B, Furukawa Hiroyasu, Paley Maria V, Velasquez Ever O, Dods Matthew N, Long Jeffrey R
Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Nature. 2023 Jan;613(7943):287-291. doi: 10.1038/s41586-022-05409-2. Epub 2023 Jan 11.
Ammonia is a critical chemical in agriculture and industry that is produced on a massive scale via the Haber-Bosch process. The environmental impact of this process, which uses methane as a fuel and feedstock for hydrogen, has motivated the need for more sustainable ammonia production. However, many strategies that use renewable hydrogen are not compatible with existing methods for ammonia separation. Given their high surface areas and structural and chemical versatility, metal-organic frameworks (MOFs) hold promise for ammonia separations, but most MOFs bind ammonia irreversibly or degrade on exposure to this corrosive gas. Here we report a tunable three-dimensional framework that reversibly binds ammonia by cooperative insertion into its metal-carboxylate bonds to form a dense, one-dimensional coordination polymer. This unusual adsorption mechanism provides considerable intrinsic thermal management, and, at high pressures and temperatures, cooperative ammonia uptake gives rise to large working capacities. The threshold pressure for ammonia adsorption can further be tuned by almost five orders of magnitude through simple synthetic modifications, pointing to a broader strategy for the development of energy-efficient ammonia adsorbents.
氨是农业和工业中的一种关键化学品，通过哈伯-博施法大规模生产。该过程以甲烷作为氢气的燃料和原料，其对环境的影响促使人们需要更可持续的氨生产方式。然而，许多使用可再生氢的策略与现有的氨分离方法不兼容。金属有机框架（MOF）因其高比表面积以及结构和化学性质的多样性，在氨分离方面具有潜力，但大多数MOF会不可逆地结合氨，或者在接触这种腐蚀性气体时发生降解。在此，我们报道了一种可调谐的三维框架，它通过协同插入其金属羧酸盐键中可逆地结合氨，形成一种致密的一维配位聚合物。这种不同寻常的吸附机制提供了可观的内在热管理，并且在高压和高温下，协同氨吸收产生了较大的工作容量。通过简单的合成修饰，氨吸附的阈值压力可进一步调整近五个数量级，这为开发节能氨吸附剂指明了更广泛的策略。
