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The separation of acetylene from carbon dioxide is challenging due to their almost identical molecular sizes and volatilities. Metal–organic frameworks (MOFs) in general are strong candidates for the separation of gas mixtures owing to the presence of functional pore surfaces that can selectively capture specific target molecules. Herein, we report a stable and easily synthesized bismuth-based MOF, Bi–BTC, which can achieve the separation of acetylene and carbon dioxide. We performed a detailed analysis of the sorption properties of the Bi–MOF. Bi–BTC shows good adsorption capacities for C2H2 with a capacity of 53.8 cm3 g−1 at 298 K and 1.0 bar, and C2H2/CO2 selectivity of 5.14/7.69 at 298 K and 1.0/0.1 bar. IAST selectivity calculations indicate that Bi–BTC possesses good separation capacity, and dynamic breakthrough experiments were performed to prove the separation of C2H2 and CO2. Bi–MOFs as a group of relatively less studied types of MOFs have interesting adsorption characteristics, and this study on Bi-based MOF will enrich three-dimensional Bi–MOF adsorbents for gas adsorption and separation applications. [ABSTRACT FROM AUTHOR]

Selective-adsorption separation is an energy-efficient technology for the capture of acetylene (C2H2) from carbon dioxide (CO2) and ethylene (C2H4). However, it remains a critical challenge to effectively recognize C2H2 among CO2 and C2H4, owing to their analogous molecule sizes and physical properties. Herein, we report a new microporous metal–organic framework (NUM-14) possessing a carefully tailored pore system containing moderate pore size and nitro-functionalized channel surface for efficient separation of C2H2 from CO2 and C2H4. The activated NUM-14 (namely NUM-14a) exhibits sufficient pore space to acquire excellent C2H2 loading capacity (4.44 mmol g−1) under ambient conditions. In addition, it possesses dense nitro groups, acting as hydrogen bond acceptors, to selectively identify C2H2 molecules rather than CO2 and C2H4. The breakthrough experiments demonstrate the good actual separation ability of NUM-14a for C2H2/CO2 and C2H2/C2H4 mixtures. Furthermore, Grand Canonical Monte Carlo simulations indicate that the pore surface of the NUM-14a has a stronger affinity to preferentially bind C2H2 over CO2 and C2H4 via stronger C-H···O hydrogen bond interactions. This article provides some insights into customizing pore systems with desirable pore sizes and modifying groups in terms of MOF materials toward the capture of C2H2 from CO2 and C2H4 to promote the development of more MOF materials with excellent properties for gas adsorption and separation. [ABSTRACT FROM AUTHOR]

A novel metal–organic framework, ZJU-196, with extraordinary acid–base resistant stability has been successfully synthesized, exhibiting highly efficient separation of acetylene from C2H2/CO2 mixtures under ambient conditions. [ABSTRACT FROM AUTHOR]

The highly ordered and designable properties of MOFs make them competitive precursors to constructing high-performance catalysts for CO 2 methanation, however, only a few studies have investigated the facilitation effect of promoters. Herein, a series of carbon encapsulated NiFe alloy nanoparticles core-shell catalysts (Ni x Fe@C, x refers to the ratio of Ni to Fe) were successfully prepared by a method of pyrolyzing Ni-MOF-74 after impregnation in Fe3+ solution for CO 2 hydrogenation to CH 4 , and their composition and structural characteristics were explored in detail by PXRD, N 2 adsorption/desorption measurements, TEM, and XPS, etc. Fe-doped catalysts exhibited significantly enhanced CO 2 methanation activity compared to the monometallic Ni catalysts, especially Ni 7 Fe@C, which reached 72.3 % CO 2 conversion with CH 4 selectivity of 99.3 % at 350 °C, and showed a CO 2 conversion of 53.3 % at 300 °C, twice that of Ni@C. The specific effects of the Fe addition on the composition and structure of the catalysts were also investigated via a combination of experiments and DFT calculations, which indicates that appropriate incorporation of Fe was conducive to promoting the dispersion of metal particles and the adsorption ability of CO 2 and CO, and thus resulted in significantly improved catalytic performance. This work provides a promising route for the rational design of MOF-derived CO 2 methanation catalysts and makes a new attempt to investigate the influence of promoters. [Display omitted] • Ni x Fe@C catalysts with evenly distributed NiFe alloy nanoparticles and core-shell structure were derived from Ni-MOF-74. • The addition of Fe significantly improved the catalytic performance of Ni@C catalyst. • Fe boosts methanation activity by promoting the dispersion of metal particles and the adsorption ability of CO 2 and CO. [ABSTRACT FROM AUTHOR]

Graphical abstract This review firstly summarized recent research progresses on the syntheses and applications of MOF-based heterogeneous catalysts for the conversion of a selection of C1 compounds, namely CO, CO 2 and CH 4 , into value-added chemicals. Highlights • MOF-based heterogeneous catalysts for C1 chemistry are systematically reviewed. • The MOFs, MOF composites and MOF derivatives catalysts are rationally summarized. • Major challenges and perspectives toward the further exploration are presented. Abstract Catalysis of C1 chemistry, especially for carbon monoxide (CO), carbon dioxide (CO 2) and methane (CH 4), is critically important for the clean production of fuels and chemicals and future energy sustainability. However, due to the relatively inert nature and low reactivity of these C1 molecules, their activation and transformation into clean fuels and high value-added chemicals still remain formidable challenges. In this context, metal-organic frameworks (MOFs), as relatively new emerging crystalline porous materials, have been shown to be promising heterogeneous catalysts or supports/precursors in the design and synthesis of various functional nanomaterials for addressing these challenges. In this review, the recent advances in MOF-based heterogeneous catalysts for transforming CO, CO 2 and CH 4 into high value-added chemicals are systematically reviewed. Emphasis is mainly placed on the catalytic reactivity, reaction mechanism and catalyst design. Additionally, major challenges and opportunities for MOF catalysts in the conversion of C1 chemistry are discussed to outline aspects for further development in this ongoing research field. It is anticipated that this review will provide a useful guide to chemists and material scientists attempting to design better MOF-based catalysts for the chemical conversion of C1 compounds. [ABSTRACT FROM AUTHOR]

With the growing attention on both environmental and energy issues, the catalytic conversion of CO 2 has gained tremendous interest of researchers. Herein, we report a bimetal CoZn-ZIF derived highly efficient catalyst CoZn-Z for CO 2 methanation. After prereduction before the catalytic test, an inverse ZnO/Co structure with plentiful uniformly dispersed active sites could be formed, and the obtained CoZn-Z catalyst showed high Co dispersion with principally exposed Co (0002) lattice plane. Sufficient active sites, increased basicity and CO adsorption resulted in enhanced CO 2 methanation catalytic activity, and CO 2 conversion of 62.9 %, CH 4 selectivity of 99.2 % with a STY CH4 of 0.21 mol CH4 ·g cat. −1·h−1 were achieved at 300 °C, 2.6 times of monometallic Co-Z and exceeding most of the reported Co-based catalysts. Furthermore, based on in situ FTIR and DFT calculation, the formation of diverse reaction intermediates was studied and different dominant reaction pathways have been proposed for CoZn-Z and Co-Z. This investigation exhibited great potential of MOFs derived catalysts as superior CO 2 methanation catalysts and elucidates the promoting effect of ZnO in Co-based CO 2 methanation catalysts for the first time. [Display omitted] • CoZn-Z catalyst with ZnO/Co reverse structure and plentiful uniformly dispersed active sites was derived from CoZn-ZIF. • CoZn-Z showed a STY CH4 of 0.21 mol CH4 ·g cat. −1·h−1 at 300 °C, 2.6 times that of its monometallic counterpart. • The promoting effect and reaction pathway on ZnO promoted Co-based methanation catalyst were studied for the first time. • ZnO boosted methanation catalytic activity by improving the metal-dispersion, alkalinity and CO adsorption strength. • The introduction of ZnO changed the dominant reaction path of CO 2 methanation over Co-based catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • A 3D MOF(GNU-3) with a local nanomolecular traps were prepared on a large scale. • Our MOF shows high SF 6 capacity and high SF 6 /N 2 selectivity. • Dynamic separation performance of SF 6 /N 2 , SF 6 /CO 2 /N 2 were revealed by breakthroughs. • Theoretical simulations identified gas more favorable trapped in nanomolecular traps. The capture of sulfur hexafluoride (SF 6) and carbon dioxide (CO 2) is an important but challenging task for reducing greenhouse gas emission and thereby diminishing negative impacts of global climate change. Herein, we integrated local nanomolecular traps into an inexpensive cobalt-based metal–organic framework (MOF, namely GNU-3) with suitable pore sizes and functional pore surfaces for capturing greenhouse gases. Activated GNU-3a showed good adsorption and separation properties for SF 6 and CO 2. Especially for SF 6 , GNU-3a displayed the high SF 6 /N 2 (10:90, v/v) selectivity of 317.6 and SF 6 uptake capacity of 2.63mmol/g at 298 K and 1.0 bar. Grand canonical Monte Carlo simulations and first-principles dispersion-corrected density functional theory calculations identified that gas molecules were favorably trapped in polyaromatic ring functionalized channel centers and nanomolecular traps of pore walls by the strong hydrogen bond interactions. Excellent breakthrough results recommend practical separating properties of GNU-3a for binary SF 6 /N 2 and CO 2 /N 2 mixtures, and ternary SF 6 /CO 2 /N 2 mixtures. Moreover, benefitting from superior features of cheap raw materials and large-scale synthesis, GNU-3 is expected to be applied to practical industrial scenarios. This work may provide insights into constructing prospectively industrial porous MOF adsorbents with optimal pore structures for greenhouse gas capture. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new environmentally safe Ca-MOF with good thermostability was synthesized. • Ca-MOF could selectively capture C 2 H 2 from C 2 H 2 /CO 2 /CH 4 ternary mixture. • The Ca-MOF represents high selectivities for C 2 H 2 /CH 4 and C 2 H 2 /CO 2 mixtures. • The systematic study of Ca-MOF as adsorbent for the capture and separation of C 2 H 2 from C 2 H 2 -containing mixtures is conducted by experimental and computational methods. High-efficiency and eco-friendly selective separation of C 2 H 2 from industrial gaseous mixtures such as CO 2 and CH 4 is of great importance in the purification and production of downstream commodity chemicals. Herein, we report a thermostable calcium-based metal–organic framework, namely NUM-20 , which could preferentially capture C 2 H 2 from C 2 H 2 -containing gaseous mixtures. NUM - 20 exhibits a higher capacity and preferential adsorption behavior of C 2 H 2 versus the competing gases including CO 2 and CH 4 , as reflected by single component gas sorption isotherms and the heat of adsorption. The IAST selectivity calculations indicate that NUM - 20 possesses multiple component separation capacity, and the transient breakthrough simulations were performed to validate the capture and separation of C 2 H 2 from multiple components. Furthermore, computational simulations were carried out to unveil the host–guest interactions under the molecular-level. This study on Ca-based MOF materials will enrich the three-dimensional Ca-based MOF adsorbents for gas capture and separation applications and address the industrial challenging separation process. [ABSTRACT FROM AUTHOR]

• Abundant Co/MnO heterointerfaces are engineered in porous graphitic carbon (PGC). • The resulted Co/MnO@PGC catalyst showed excellent catalytic performance during the low temperature CO 2 methanation. • In situ generated Co/MnO heterointerfaces promote CO 2 adsorption and facilitate CO 2 activation. • A synergy between Co0 and MnO at the Co/MnO heterointerface is responsible for the superior performance of Co/MnO@PGC. Direct conversion of CO 2 into CH 4 provides an eco-friendly way of mitigating CO 2 emissions and reducing the demand for fossil fuels, but this process was kinetically hindered under low temperature because of the high stability of CO 2 molecule. The search for efficient low-cost catalysts capable of converting CO 2 into CH 4 with a high space-time yield (STY CH4) at low temperature is becoming more desirable. Here we report a highly efficient, stable and core-shell catalyst with abundant Co/MnO heterointerface inside porous graphitic carbon (Co/MnO@PGC), which can be easily obtained by one-step calcination of a bimetal-organic framework (CoMn-MOF-74). The combination of various the nanoscale characterizations and theoretical modeling ascertain that the in situ generated Co/MnO heterostructured nanoparticles (NPs) not only create many metal defects and oxygen vacancies, but also enhance the Co-MnO interaction at Co/MnO heterointerface, which promote CO 2 adsorption and facilitate CO 2 activation. The resulting Co/MnO@PGC is able to convert CO 2 to CH 4 at temperature even as low as 160 °C with >99% selectivity and exceptional high STY CH4 of 0.14 μmol CH4 ·s−1·g cat. −1, surpassing by far the most active Co catalysts reported up to now under the identical condition. Most astonishingly, at a higher pressure (30 bar), the STY CH4 can reach up to 5.60 μmol CH4 ·s−1·g cat. −1 at 160 °C, which is comparable to the optimal level of Ru-based catalyst, and simultaneously sets a new benchmark for the Co-based methanation catalyst. On the basis of catalytic studies and in situ FTIR spectroscopy of CO 2 methanation experiments, the active sites responsible for this superior performance for Co/MnO@PGC can be associated with a synergy between Co° and MnO at the Co/MnO heterointerface, where H 2 is efficiently dissociated on the Co° and the strong adsorption and activation of CO 2 taking place on the adjacent MnO. This work provides a promising way for the design of advanced CO 2 methanation catalysts. [ABSTRACT FROM AUTHOR]