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Utilizing renewable energy to hydrogenate carbon dioxide into fuels eliminates massive CO2 emissions from the atmosphere and diminishes our need for using fossil fuels. This review presents the most recent developments for designing heterogeneous catalysts for the hydrogenation of CO2 to formate, methanol, and C2+ hydrocarbons. Thermodynamic challenges and mechanistic insights are discussed, providing a strong foundation to propose a suitable catalyst. The main body of this review focuses on nanostructured catalysts for constructing efficient heterogeneous systems. The most important factors affecting catalytic performance are highlighted, including active metals, supports and promoters that can potentially be used. The summary of the results and the outlook are presented in the final section. During the past few decades, heterogeneous CO2 hydrogenation has gained much attention and made tremendous progress. Thus, many highly efficient catalysts have been studied to discover their active sites and provide mechanistic insights. This paper summarizes recent advances in CO2 hydrogenation and its conversion into various hydrocarbons such as formate, methanol, and C2+ products. As for formate production, Au and Ru nanocatalysts show superior activity. However, considering the catalyst cost, Cu‐based catalysts have an excellent prospect for methanol production, among other catalysts. Ultra‐small nanoparticles and nanoclusters appear promising to provide highly active cost‐effective catalysts. A growing number of researchers are investigating the possibility of directly synthesizing C2+ products through CO2 hydrogenation. The major challenge in producing heavy hydrocarbons is breaking the ASF limitations, which have been achieved over bifunctional catalysts using zeolites. Using suitable support and promoter can lead to a superior activity, ascribed to structural, electronic, and chemical promotional effects. [ABSTRACT FROM AUTHOR]

[Display omitted] • The recent progress of membrane-based chiral separation is reviewed. • Chiral molecular recognition theory as well as membrane separation mechanism are discussed. • The current porous polymer membrane are highlighted in terms of enantioseparation. • The prospects and challenges of chiral separation are proposed. Chiral separation is essential in discovering bioactive substances because the enantiomer of chiral drugs usually exhibits different or even opposite biological activity and toxicity. As a result, the development of novel strategies to separate enantiomers has been an active area worldwide. Among these, membrane separation has become an emerging technology and is considered the most promising process for large-scale production due to its energy efficiency, low cost, and ease of operability. Currently, many advances in chiral separation using chiral or non-chiral membranes have been achieved, while the systematic reviews of such processes and critical materials thereof are few. This review presents a survey of the advances in the enantio-separation technique using solid and liquid membranes. In particular, the present polymeric chiral separation membranes, such as non-chiral polymer membranes, chiral dense and porous membranes, and mixed-matrix membranes, are extensively reviewed. Other membranes, such as biomembranes and liquid membranes, are also discussed for comparison. In addition, the study presents a comprehensive summary and discussion of the state-of-the-art development and prospects of such materials to provide relevant guidance for improving the performance of membrane chiral separation. [ABSTRACT FROM AUTHOR]

Membrane gas separation processes represent a crucial platform for achieving carbon neutral climate goals. CO 2 -philic membranes offer excellent solubility selectivity due to their high affinity, thereby allowing the separation of gas fractions with similar molecular sizes or smaller than CO 2 molecules. This level of separation is difficult to achieve with conventional diffusion-dominated separation membranes. However, the gas permeability of PEO membranes is often hampered by dense chain packing and crystallization behavior. To overcome this challenge, we employed a molecular engineering approach to develop a unique PEO membrane with a hyperbranched chemical topology connection. The packing density of the polymer chains was effectively regulated by employing cross-linker molecules with distinct spatial configurations, while the free volume fraction was successfully reinforced. This unique molecular engineering strategy led to the creation of a PEO membrane exhibiting superior performance that surpassed the limit of the 2019 upper-bound line. This work demonstrated a molecular design strategy for the precise control of structural attributes in crosslinked PEO networks, offering an alternative solution for developing CO 2 capture membranes and enabling further opportunities for rational membrane material design. [Display omitted] • Cross-linked PEO membranes with various topological structure were constructed. • Molecular engineering optimized the free volume of cross-linked network. • The gas diffusion in cross-linked PEO membranes was promoted substantially. • The CO 2 /N 2 separation performance exceeded the 2019 upper bound. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two new PIMs were synthesized and applied for CO 2 capture. • High CO 2 working capacity was obtained. • Good dynamic CO 2 /N 2 mixture separation performance was obtained. • A dissolution-separation-precipitation (DSP) approach was proposed and proved. • Distinguished renewability after fouling. Anthropogenic carbon dioxide emission has been an urgent environmental and climate issue, yet remains a challenge to address. Solid adsorbents are potential candidates for CO 2 capture while their insolubility nature makes the regeneration problematic when fouled. Here we report the synthesis of a thioamide incorporated polymer of intrinsic microporosity, TPIM, which features high intrinsic microporosity with specific surface areas of 531 m2/g, and good solubility in selected organic solvents such as THF, DMSO and DMAc. Static physisorption and kinetic breakthrough experiments revealed several promising features of TPIM: high CO 2 capacity of 2.45 mmol/g at 1 bar and 298 K, good CO 2 /N 2 mixture dynamic separation performance, and facile regeneration ability. Most interestingly, its porosity and CO 2 capacity could be easily restored through a simple dissolution-separation-precipitation (DSP) approach, making it regenerative when fouled, providing a new insight for the future design of regenerable adsorbents. [ABSTRACT FROM AUTHOR]