Shotaro Hiraide

Establishing new energy-saving systems for gas separation using porous materials is indispensable for ensuring a sustainable future. Herein, we show that ELM-11 ([Cu(BF₄)₂(4,4'-bipyridine)₂]_n), a member of flexible metal-organic frameworks (MOFs), exhibits rapid responsiveness to a gas feed and an 'intrinsic thermal management' capability originating from a structural deformation upon gas adsorption (gate-opening). These two characteristics are suitabl

We show that flexible metal-organic frameworks (MOFs) exhibiting "gate openings/closings" for CO₂ can intrinsically suppress the exothermic heat released by adsorption and the endothermic heat gained by desorption, both of which reduce the working capacity of CO₂ in a separation process under near-adiabatic conditions. We use the elastic layer-structured metal-organic framework-11 (ELM-11) [Cu(4,4'-bipyridine)₂(BF₄)₂], which exhibits a two-s

Porous sorbents are materials that are used for various applications, including storage and separation. Typically, the uptake of a single gas by a sorbent decreases with temperature, but the relative affinity for two similar gases does not change. However, in this study, we report a rare example of "crossover sorption," in which the uptake capacity and apparent affinity for two similar gases reverse at different temperatures. We synthesized two soft porous coordination polymers (PCPs), [Zn<sub>2

Flexible metal-organic frameworks (MOFs) exhibit an adsorption-induced structural transition known as "gate opening" or "breathing," resulting in an S-shaped adsorption isotherm. This unique feature of flexible MOFs offers significant advantages, such as a large working capacity, high selectivity, and intrinsic thermal management capability, positioning them as crucial candidates for revolutionizing adsorption separation processes. Therefore, the interest in the industrial applications of flexib

As flexible metal–organic frameworks (MOFs) and their gate adsorption behaviors are increasingly expected to be used in gas storage and separation systems, evaluating their performance by considering their usage patterns in actual processes is becoming increasingly important. Herein, we show that the shaping of the elastic layer-structured MOF-11 (ELM-11; [Cu(BF4)2(4,4′-bipyridine)2]) into pellet forms using polymer binders smears its stepwise uptake associated with the CO2 gate adsorption. This

Current energy issues have driven the development of high-throughput separation processes using solid adsorbents as an alternative to distillation. However, it is a crucial problem that the temperature increase due to adsorption heat significantly reduces the adsorption performance because of near adiabatic operations. Herein, we discuss thermal management using phase change materials (PCMs) in such processes based on a combination of experimental and theoretical studies. Breakthrough curve meas

Flexible-robust metal-organic frameworks (MOFs), which exhibit unique hybrid nature comprising both flexible and rigid framework characteristics, exhibit high potential for hydrocarbon separations. However, no clear guidelines have been established to regulate their hybrid characteristics owing to limited understanding of their adsorption mechanism. This study investigates the effects of the particle size of a flexible-robust MOF on its adsorption and structural transition behaviors. The robust

Flexible metal-organic frameworks (MOFs) are innovative adsorbents expected to revolutionize conventional separation systems as they exhibit stepwise adsorption arising from structural transitions, commonly known as "gate opening." However, because MOFs are typically obtained in powder form, they require shaping for industrial applications. In our previous study, we reported that the stepwise uptake observed in the CO₂ gate opening of ELM-11 ([Cu(BF₄)₂(4,4<i>'</i

The phase of the precursor of ELM-11 affects the steepness of its gate-opening behavior, and this phase can be controlled by solvent-mediated phase transformation.

Flexible metal–organic frameworks (MOFs) show S-shaped adsorption isotherms due to their structural transition. This behavior changes depending on their particle size. This paper elucidates the size effect using a multi-scale simulation model.

Flexible metal-organic frameworks (MOFs) exhibit stepped adsorption isotherms due to structural transitions between narrow-pore (np) and large-pore (lp) states. This characteristic stepwise uptake at a certain pressure results in adsorptive high working capacities, making these materials highly effective for energy-efficient gas storage and separation processes. The transition pressure, which is key to enhancing separation efficiency, can be tuned by varying the particle size of flexible MOFs. H

Porous carbons play vital roles in adsorption-based applications, and their pore size distributions (PSDs) are crucial for performance. Kernel-based inversion of adsorption isotherms is the standard route to obtain PSDs, yet it still faces technical limitations. In this study, we address these issues by combining grand canonical Monte Carlo (GCMC) simulation with a Bayesian statistical framework. GCMC provides a thermodynamically rigorous description of adsorption, surpassing classical density f