# Polymeric and Crystalline Materials for Effective and Sustainable CO\({}_{2}\) Capture
## 7 Challenges and Future Perspectives  
For critical industrial processes, such as gas separation and post-combustion capture, MOF-based membrane technologies offer a promising alternative to traditional energy-intensive unit operations. This is attributed to their remarkable adsorption capacity, thermal and hydrolytic stability, and chemical robustness. However, this technology requires further maturation and scaling up. Currently, the gas capture and separation markets are dominated by commercial polymeric materials and traditional scrubbers, most of which were developed before the 1990s. This highlights a stagnation in the development of new materials necessary to meet the increasing demands in this field. Metal-organic frameworks constitute exhibit significant potential to address the performance and stability limitations \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Technology Name** & **TRL \({}^{*}\)** & **Energy Demand** & **Price per ton of** & **Reference** \\  & & **[kWh/T CO\({}_{2}\)]** & **Captured CO\({}_{2}\) [US \$/T]** & **[210]** \\ \hline Amine scrubbing (monoethanol & & & & \\ amine), post-combustion & 9 & 400–500 & 29–55 & [210] \\ \hline O\({}_{2}\)/CO\({}_{2}\) recycle combustion (oxyfuel combustion) & 9 & 100–200 & 35 & [211] \\ \hline Selexol **, pre-combustion & 8–9 & 200–300 & 5–28.8 & [212; 213] \\ \hline MOF-based mixed matrix membranes, pre-combustion capture & 4 & 150 & 16.9 & [214] \\ \hline MOF-based mixed matrix membranes, post-combustion capture & 4 & 240 & 30 & [214] \\ \hline \hline \end{tabular}  
* TRL stands for technology readiness level and measures the maturity of a technology from initial concept (TRL 1) to full deployment (TRL 9). **Slexol processes use a physical solvent (Selexol) made of dimethyl ethers of polyethylene glycol to selectively remove H\({}_{2}\)S/carbonyl sulfide and remove CO\({}_{2}\) in bulk from gas streams.  
\end{table} 
Table 2: Techno-economic analysis comparison of CO\({}_{2}\) capture technologies. observed in many polymers under industrially relevant conditions [225; 226]. [PERSON] et al. brilliantly concluded that over the past 50 years, nearly 100,000 new MOF structures have been discovered, with 50% of these identified in the last 7 years alone, underscoring the remarkable and rapid advancement of this technology. [36]. Researchers are increasingly drawn to MOFs due to their precise tunability of pore dimensions, the ability to covalently decorate and exchange ligands, and their chemical and thermal stability [225]. These features enable exploration of the diverse architectural and chemical variability of MOFs, allowing for membrane performance metrics that surpass previously reported standards. Zeolitic imidazolate frameworks are particularly notable for their consistently high performance and excellent thermal stability, making them promising candidates for further investigation and large-scale applications [227]. Despite the numerous advantages of MOFs, the transition from laboratory research to industrial-scale application faces several significant challenges. Regardless of the discovery of nearly 100,000 MOF structures, scale-up precedents are scarce, hindering the broader adoption of MOF technologies. Cost efficiency remains a critical hurdle, as current production methods are not economically viable for large-scale operations [228]. Additionally, the fabrication of defect-free, continuous MOF films is still not well understood, limiting their practical use as a functional membrane. Furthermore, [PERSON] et al. highlight that the separation performance of COF and MOF membranes in the presence of detrimental impurities remains unexplored [229; 230]. Hybrid MOFs and ZIFs, such as mixed-linker or mixed-metal MOFs, present an exciting area of research due to their potential for enhanced performance. However, the structure-activity relationships in these materials are poorly understood, complicating their design and optimization.