Junsu Jin

Trace propylene (C3H6) removal from ethylene (C2H4) in methanol-to-olefins (MTO) processes remains a pivotal challenge owing to their similar physicochemical properties and the detrimental effect of moisture on most adsorbents. Herein, we report a water-stable metal–organic framework, Cu-BTC-Ntrz, constructed by anchoring nitro-triazole (Ntrz) onto the open metal sites of Cu-BTC. This Ntrz modification serves a dual purpose: it shields the copper centers from hydrolytic attack, preserving full structural integrity after immersion in 353 K water for three days, and installs synergistic binding sites (C-H···N, C-H···π, and C-H···O interactions) that dramatically enhance C3H6 affinity. Cu-BTC-Ntrz exhibits a record-high C3H6 uptake at 0.01 bar (83.9 cm3 g-1), an ultrahigh Henry’s coefficient (48822.6 cm3 g-1 bar-1), and an IAST selectivity of 28.4 for equimolar C3H6/C2H4 mixtures. Dynamic breakthrough experiments confirm polymer-grade C2H4 purity exceeding 99.999% with a productivity of 1591.7 L kg-1, outperforming most benchmark materials. Remarkably, the synthesis cost (281.4 USD kg-1) delivers a cost-normalized productivity of 253.8 mmol USD-1. By integrating record separation performance with exceptional water stability and low synthesis cost, Cu-BTC-Ntrz establishes a new benchmark for energy-efficient C3H6/C2H4 separation and paves the way toward practical ethylene purification from MTO products.

Metal–organic frameworks (MOFs) show great potential for post-combustion carbon capture, yet their practical application is often constrained by challenges such as powder handling difficulties, limited structural stability during shaping processes, and performance degradation under high-humidity conditions. In this study, Mg-gallate was structured into millimeter-sized Mg-gallate/CA composite beads via the ionotropic gelation method, and then a hydrophobic layer of vinyltrimethoxysilane (VTMS) was constructed on the bead surface by chemical vapor deposition. The synthesized Mg-gallate/CA and V-Mg-gallate/CA are characterized by XRD, FT-IR, and other techniques, and their CO₂ adsorption behavior, adsorption–desorption kinetics, breakthrough performance, and cyclic stability are systematically evaluated. At 298 K and 0.1 bar, the CO₂ adsorption capacity of Mg-gallate/CA reached 94.2% of that of Mg-gallate powder. The microporous–microporous hierarchical structure constructed by the ionotropic gelation method improved the CO₂ capture efficiency of the composite beads by 16.7% at 0.1 bar. V-Mg-gallate/CA maintained a high dynamic CO₂ adsorption capacity of 2.87 mmol/g for a 10 vol.% CO₂/90 vol.% N₂ gas mixture at 298 K under 80% RH, corresponding to 2.04 times the capacity of Mg-gallate/CA, and retained 98.8% of its initial adsorption capacity at 0.1 bar after 10 cycles. Combining ionotropic gelation shaping with surface hydrophobic modification represents an effective strategy for developing MOF-based adsorbents suitable for post-combustion CO₂ capture.

Metal-organic frameworks (MOFs) have emerged as exceptional materials for atmospheric water harvesting (AWH) due to their superior adsorption properties in low humidity conditions (≤20% RH), but most MOF adsorbents typically exist in powder form, thus their aggregation induces significant transfer resistance to limit their adsorption kinetics and practical application potential. Here we prepared an organic-inorganic MOF-303@poly(acrylates) composite by in-situ growing MOF-303 within porous poly(acrylates) spheres. Our results demonstrate that the 87% loading of MOF-303@poly(acrylates) exhibits uniformly dispersed crystals with a crystal size that is 40% smaller compared to pure MOF-303 powder, while maintaining a water vapor adsorption capacity of 0.348 g g^-1 at 20% RH and 298 K, which is comparable to that of an equivalent mass of the pure MOF-303 powder. In the dynamic water vapor test with a constant flow rate (50 mL min^-1), the adsorption and desorption rates of the composite are 2.74 times and 2 times faster than those of MOF-303 powder. After 100 consecutive adsorption and desorption cycles at 1780 mL min^-1 (0.95 m s^-1, light air), the water vapor adsorption capacity showed no significant decline. This composite strategy not only enhances adsorption kinetics but also advances MOF-based AWH systems for engineering applications.

Liquid–liquid interfacial tension (LL-IFT) and the associated nanoscale interfacial structure are key to an extraction-based separation process. Here, we apply the perturbed-chain statistical associating fluid theory (PC-SAFT)-based classical density functional theory (cDFT) to predict the LL-IFT, interfacial density, and hydrogen-bonding profiles of methanol–n-alkane (n-hexane, n-heptane, and n-octane) mixtures under atmospheric pressure. Each mixture is modeled by using a single temperature-independent binary interaction parameter. To determine the optimal modeling strategy, we systematically assess six combinations derived from four published PC-SAFT parameter sets for methanol and three nonlocal association functionals (i.e., aFMT, aWDA, and iSAFT). The first three parameter sets incorporated the vapor pressure, saturated liquid density, and vapor–liquid interfacial tension (VL-IFT) into the fitting process, with VL-IFT calculated by aFMT, aWDA, and iSAFT for sets 1, 2, and 3, respectively. Parameter set 4 was optimized exclusively to the bulk phase equilibrium data. Notably, despite their superior accuracy in predicting binary VL-IFT, parameter sets 1–3 do not outperform set 4 in predicting binary LL-IFT. Furthermore, both iSAFT and aWDA show good agreement with experimental LL-IFT data, whereas aFMT consistently overestimates the values across all systems and temperatures, irrespective of the methanol parameters used. Although the optimal combination varies by system, the overall performance of the current cDFT framework demonstrates remarkable precision in reproducing LL-IFT. From a structural perspective, monotonic density and hydrogen-bonding profiles with intersection points have been identified: two for density profiles (one per component) and one for hydrogen-bonding profiles.

Ultrastable Y (USY) with intracrystalline mesoporosity as the main active component plays a crucial role in the fluid catalytic cracking (FCC) of heavy oil. To obtain this material, mesoporous NaY was first synthesized using an organic template and then treated through multistep ammonium ion exchange/hydrothermal treatment. However, this complex procedure results in high synthesis costs and environmental pollution. In this article, a simple and effective strategy called "heteroatom substitution" was developed to introduce intracrystalline mesopores into zeolite NaY. The products obtained by this method exhibited a well-ordered microstructure with a large external surface area. XRD, XPS, and TOF-SIMS analyses confirmed that Li atoms were incorporated into the zeolite framework. In the subsequent procedure, a process known as "gas-phase ultrastabilization" was conducted by the direct reaction of solid zeolite NaY with gas-phase SiCl₄. This process could lead to the simultaneous removal of aluminum and sodium from the zeolite framework. As a result of this, USY with intracrystalline mesoporosity exhibited significantly enhanced catalytic cracking properties toward heavy oil.

In₂O₃ is an effective electrocatalyst to convert CO₂ to formic acid (HCOOH), but its inherent poor electrical conductivity limits the efficient charge transfer during the reaction. Additionally, the tendency of In₂O₃ particles to agglomerate during synthesis further limits the exposure of active sites. Here we address these issues by leveraging the template effect of graphene oxide and employing InBDC as a self-sacrificing template for the pyrolysis synthesis of In₂O₃@C. The resulting In₂O₃@C/rGO-600 material features In₂O₃@C nanocubes uniformly anchored on a support of reduced graphene oxide (rGO), significantly enhancing the active sites exposure. The conductive rGO network facilitates charge transfer during electrocatalysis, and the presence of oxygen vacancies generated during pyrolysis, combined with the strong electron-donating ability of rGO, enhances the adsorption and activation of CO₂. In performance evaluation, In₂O₃@C/rGO-600 exhibits a remarkable HCOOH Faradaic efficiency exceeding 94.0% over a broad potential window of −0.7 to −1.0 V (vs. reversible hydrogen electrode (RHE)), with the highest value of 97.9% at −0.9 V (vs. RHE) in a H-cell. Moreover, the material demonstrates an excellent cathodic energy efficiency of 71.6% at −0.7 V (vs. RHE). The study underscores the efficacy of uniformly anchoring metal oxide nanoparticles onto rGO for enhancing the electrocatalytic CO₂ reduction performance of materials.