Sacrificing the CO2 capacity by reducing the loading of amines may be desirable if it improves mass transfer. Alumina is a particularly encouraging porous support due to its high conductivity, low specific heat capacity, and stability in the presence of steam. In particular, the pores of whatever porous structure is used should be expanded as much as possible without losing excessive mechanical strength to maximise mass transfer. Although, the impact of pore expansion on adsorbent density should also be investigated. We also acknowledge that other key factors exist beyond those considered here, such as synthesisability and cyclic stability, which will impact the eventual feasibility of an adsorbent.