The realization of porous materials for highly selective separation of acetylene (C2H2) from various other gases (e.g., carbon dioxide and ethylene) by adsorption is of prime importance but challenging in the petrochemical industry. Herein, a chemically stable Hofmann‐type metal−organic framework (MOF), Co(pyz)[Ni(CN)4] (termed as ZJU‐74a), that features sandwich‐like binding sites for benchmark C2H2 capture and separation is reported. Gas sorption isotherms reveal that ZJU‐74a exhibits by far the record C2H2 capture capacity (49 cm3 g−1 at 0.01 bar and 296 K) and thus ultrahigh selectivity for C2H2/CO2 (36.5), C2H2/C2H4 (24.2), and C2H2/CH4 (1312.9) separation at ambient conditions, respectively, of which the C2H2/CO2 selectivity is the highest among all the robust MOFs reported so far. Theoretical calculations indicate that the oppositely adjacent nickel(II) centers together with cyanide groups from different layers in ZJU‐74a can construct a sandwich‐type adsorption site to offer dually strong and cooperative interactions for the C2H2 molecule, thus leading to its ultrahigh C2H2 capture capacity and selectivities. The exceptional separation performance of ZJU‐74a is confirmed by both simulated and experimental breakthrough curves for 50/50 (v/v) C2H2/CO2, 1/99 C2H2/C2H4, and 50/50 C2H2/CH4 mixtures under ambient conditions.

The pore size and low-polarity pore surface are systematically engineered within a series of C2H6-selective MOF materials for targeting high C2H6 uptake capacity, high C2H6/C2H4 selectivity and moderate C2H6 adsorption heat simultaneously.

Separation of acetylene from carbon dioxide remains a daunting challenge because of their very similar molecular sizes and physical properties. We herein report the first example of using copper(I)‐alkynyl chemistry within an ultra‐microporous MOF (CuI@UiO‐66‐(COOH)2) to achieve ultrahigh C2H2/CO2 separation selectivity. The anchored CuI ions on the pore surfaces can specifically and strongly interact with C2H2 molecule through copper(I)‐alkynyl π‐complexation and thus rapidly adsorb large amount of C2H2 at low‐pressure region, while effectively reduce CO2 uptake due to the small pore sizes. This material thus exhibits the record high C2H2/CO2 selectivity of 185 at ambient conditions, significantly higher than the previous benchmark ZJU‐74a (36.5) and ATC‐Cu (53.6). Theoretical calculations reveal that the unique π‐complexation between CuI and C2H2 mainly contributes to the ultra‐strong C2H2 binding affinity and record selectivity. The exceptional separation performance was evidenced by breakthrough experiments for C2H2/CO2 gas mixtures. This work suggests a new perspective to functionalizing MOFs with copper(I)‐alkynyl chemistry for highly selective separation of C2H2 over CO2.

Two-dimensional transition-metal dichalcogenides (TMDCs) possess unique electronic and optical properties, which open up a new opportunity for atomically thin optoelectronic devices. Synthesizing large-scale monolayer TMDCs on the SiO 2 /Si substrate is crucial for practical applications, however, it remains a big challenge. In this work, a method which combines chemical vapor deposition (CVD) and thermal evaporation was employed to grow monolayer tungsten disulfide (WS 2 ) crystals. Through controlling the density and the distribution of W precursors, a wafer-scale continuous uniform WS 2 film was achieved, with the structural and spectral characterizations confirming a monolayer configuration and a high crystalline quality. Wafer-scale field-effect transistor arrays based on the monolayer WS 2 were fabricated. The devices show superior electrical performances, and the maximal mobility is almost 1 order of magnitude higher than those of CVD-grown large-scale TMDC devices reported so far.

separations. [1] Ethylene (C 2 H 4 ), as the most important olefins, is the mainstay of petrochemical industry, with a global annual production of exceeding 170 million tonnes per year. "Polymer-grade" specification of ethylene is required for the manufacture of polyethylene plastic. The industrial separation of ethylene from ethylene/ethane (C 2 H 4 /C 2 H 6 ) mixtures highly relies on the repeated distillation-compression cycling at the temperature as low as −160 °C. [1,2] Such heat-driven separation involving in the phase change of isolated fractions, is highly energy-and capital-intensive. Finding energy-efficient alternatives to distillation would widely lower global energy consumption, carbon emissions, and pollution. It is feasible in principle to separate C 2 H 4 /C 2 H 6 mixtures based on porous solid materials via the energy-efficient and environmentally friendly adsorption technology. In this context, development of suitable porous adsorbents for ethylene/ ethane separation is of highly commercial significance.A number of porous materials including zeolites, [3] carbon molecular sieves, [4] and alumina, [5] have been explored for the separation of ethylene and ethane. However, the limits on deliberately designing the structure of such purely inorganic materials make them hardly meet the requirement of industrial implement. As an emerging class of microporous The development of new materials for separating ethylene (C 2 H 4 ) from ethane (C 2 H 6 ) by adsorption is of great importance in the petrochemical industry, but remains very challenging owing to their close molecular sizes and physical properties. Using isoreticular chemistry in metal-organic frameworks (MOFs) enables the precise design and construction of target materials with suitable aperture sizes and functional sites for gas separations. Herein, it is described that fine-tuning of pore size and π-complexation simultaneously in microporous copper(I)-chelated MOFs can remarkably boost the C 2 H 4 /C 2 H 6 adsorption selectivity. The judicious choice of organic linkers with a different number of carboxyl groups in the UiO-66 framework not only allows the fine tuning of the pore size but also immobilizes copper(I) ions onto the framework. The tailor-made adsorbent, Cu I @UiO-66-(COOH) 2 , thus possesses the optimal pore window size and chelated Cu(I) ions to form π-complexation with C 2 H 4 molecules. It can rapidly adsorb C 2 H 4 driven by the strong π-complexation interactions, while effectively reducing C 2 H 6 uptake due to the selective size-sieving. Therefore, this material exhibits an ultrahigh C 2 H 4 /C 2 H 6 selectivity (80.8), outperforming most previously described benchmark materials. The exceptional separation performance of Cu I @UiO-66-(COOH) 2 is validated by breakthrough experiments for 50/50 v/v C 2 H 4 /C 2 H 6 mixtures under ambient conditions.