Metal organic frameworks (MOFs) as adsorbents present a potentially cost effective and energy saving alternative to current technologies used to purify carbon monoxide (CO), a reagent in numerous industrial processes. This review compares the different mechanisms involved in CO adsorption in MOFs, highlighting the desired chemical and structural features for this process. An outlook on future directions for research on MOFs for CO adsorption is proposed.

Carbon monoxide (CO)/nitrogen (N 2 ) separation is a particularly challenging separation, yet it is the one with great industrial relevance for its use in petrochemical synthesis. Although an expensive cryogenic step can be used to perform such separation, it remains ineffective in purifying CO from syngas streams with a significant N 2 content. Taking advantage of the lower energy requirement of adsorption processes, we have explored the use of metal−organic frameworks (MOFs) as adsorbents for this difficult separation. We have screened a range of MOF candidates for CO/N 2 separation covering a range of chemical and textural features, using the flux response technology to evaluate their dynamic performance for throughput testing alongside equilibrium uptake measurements. We have identified Ni-MOF-74 and Co-MOF-74 as the most promising candidates because of their high metal density and strong metal−CO interactions. We have investigated further the effect of N 2 impurity concentrations upon CO/N 2 separation using breakthrough adsorption testing and cyclic testing (up to 20 cycles). Overall, using multiple adsorption measurement techniques, this study demonstrates the CO/N 2 dynamic separation performance of M-MOF-74 and its ability to be applied for an industrially relevant separation.

Efficient removal of CO2 from enclosed environments is a significant challenge, particularly in human space flight where strict restrictions on mass and volume are present. To address this issue, this study describes the use of a multimaterial, layer-by-layer, additive manufacturing technique to directly print a structured multifunctional composite for CO2 sorption with embedded, intrinsic, heating capability to facilitate thermal desorption, removing the need for an external heat source from the system. This multifunctional composite is coprinted from an ink formulation based on zeolite 13X, and an electrically conductive sorbent ink formulation, which includes metal particles blended with the zeolite. The composites are characterized using analytical and imaging tools and then tested for CO2 adsorption/desorption. The resistivity of the conductive sorbent is <2 mΩ m, providing a temperature increase up to 200 °C under 7 V applied bias, which is sufficient to trigger CO2 desorption. The CO2 adsorption capability of the conductive zeolite ink appears to be unaffected by the presence of the conductive particles, meaning a large fraction of the total mass of the structured composite device is functional.

The separation of CO/N2 mixtures is a challenging problem in the petrochemical sector due to the very similar physical properties of these two molecules, such as size, molecular weight and...

We present an in situ study of CO adsorption on Cu impregnated MOF-74 and study the competitive adsorption of CO vs. CO2 and N2.