Carbon Capture Beyond Amines: CO₂Sorption at Nucleophilic Oxygen Sites in Materials

Abstract

Carbon capture and utilization or sequestration and direct air capture will be needed to reduce atmospheric levels of greenhouse gases over the next century. Current aminebased technologies bind CO 2 with high selectivities but suffer from poor oxidative and thermal stabilities. Herein, we discuss understudied sorbents based on oxygen nucleophiles, including metal oxides and hydroxides, hydroxide-containing polymers, and hydroxide-based metal-organic frameworks. In general, these materials display improved oxidative stabilities compared to traditional amine-based sorbents. We outline the challenges and opportunities offered by these alternative sorbents for carbon capture applications.

Benchmarking nitrous oxide adsorption and activation in metal–organic frameworks bearing coordinatively unsaturated metal centers

“…11 They are crystalline, highly porous materials formed by connecting metal secondary building units (SBU) with multitopic organic linkers. MOFs have been designed to selectively bind CO 2 and CH 4 based on electrostatic interactions, 12,13 chemical reactivity, [14][15][16] hydrogen bonding, 17 and more. In contrast, only a small number of largely unrelated MOFs have been studied for N 2 O capture to date.…”

Capturing Carbon Dioxide from Air with Charged Sorbents

“…2,3 Hydroxide-based scrubbers are among the most promising for DAC. 4,5 For example, an industrially mature approach employs aqueous KOH solutions as the sorbent, 6 but a high energy regeneration step at 900 ºC and the use of natural gas is required. A related approach under commercialisation uses solid calcium hydroxide as the sorbent, again with regeneration at 900 ºC.…”

Benchmarking Nitrous Oxide Adsorption and Activation in Metal-Organic Frameworks Bearing Coordinatively Unsaturated Metal Centers

“…11 They are crystalline, highly porous materials formed by connecting metal secondary building units (SBU) with multitopic organic linkers. MOFs have been designed to selectively bind CO2 and CH4 based on electrostatic interactions, 12,13 chemical reactivity, [14][15][16] hydrogen bonding, 17 and more. In contrast, only a small number of largely unrelated MOFs have been studied for N2O capture to date.…”