MXenes have gained deep interest in various applications since the discovery of their first member, Ti 3 C 2 T x , in 2011 due to their exceptional properties. They are accepted as promising candidates for gas separation applications. Here, we aimed to identify CO 2 /H 2 adsorption-based separation performances of blooming MXene family including 730 members under various process conditions via molecular simulations.We reported that 62% and 83% of MXenes revealed percent regenerability (R%) >90% for single gas adsorption under pressure and vacuum swing adsorption conditions, respectively while these percentages reached 98% and 95% with the increase in interlayer distance. Ti 0.4 Nb 1.6 C, V 2 Ti 2 C 3 , Ti 2 VC 2 , and Ti 1.2 Nb 0.8 C are best MXenes in single gas adsorption whereas for CO 2 /H 2 :25/75 mixture, top MXenes dominantly consist of Cr, Mo, and W. We reported an online MXene database (https://mem-ces. com/mxenes/) which covers simulated adsorbent metrics of MXenes for CO 2 /H 2 separations. Examining this MXene database would be beneficial to conceptually understand MXene design for CO 2 /H 2 separation.

The H 2 /CO 2 gas separation is extremely emerging both for the production of H 2 which is useful as an energy source/fuel due to high energy content per unit of weight and capturing the CO 2 emissions that cause global warming and climate change. The adsorption method has come to the fore because it requires less energy for the separation process than other technologies and has a reduced environmental impact. In order to determine the promising adsorbent, it is really time-consuming and cost-intensive to carry out experimental studies for each adsorbent material. Since the capability and efficiency of molecular simulation methods are too high, recently they are emerged to reveal the adsorption performance of existing adsorbent materials. In this review study, we aimed to identify the performance of inorganic porous adsorbents that were defined by molecular simulation approaches. For this scope, we considered three metrics for adsorbents such as CO 2 adsorption capacity, CO 2 /H 2 adsorption selectivity, and isotherm obtained depending on pressure. Accordingly, it was proposed from the literature survey that HP adsorbent for pure CO 2 adsorption, PAF-1 for CO 2 /H 2 adsorption selectivity and diamondyne for CO 2 /H 2 adsorption selectivity at high pressures attracted attention. As a result, we aimed to guide the experiments in choosing the adsorbent material from the data collected and proposed from simulation studies.