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The adsorption and mass transport of CO 2 and CH 4 in CHA zeolite were studied experimentally. First, large and well-defined CHA crystals with varying Si/Al ratios and morphologies ideal for adsorption studies were prepared. Then, adsorption isotherms were measured, and adsorption parameters were estimated from the data. In the next step, permeation experiments for pure components and mixtures were conducted for a defect-free CHA membrane with a Si/Al ratio of 80 and a thickness of 600 nm over a wide temperature range. A maximum selectivity of 243 in combination with a CO 2 permeance of 70 × 10−7 mol/(m2 s Pa) was observed for a feed of an equimolar CO 2 /CH 4 mixture at 273 K and 5.5 bar. Finally, a simple model accounting for adsorption and diffusion through the surface barriers and the interior of the pores of the membrane was fitted to the permeation data. The fitted model indicated that the surface barrier was a surface diffusion process at the pore mouth with higher activation energy than the diffusion process within the pores. The model also showed that the highly selective mass transport in the membrane was mostly a result of a selective surface barrier and, to a lesser extent, a result of adsorption selectivity. [Display omitted] • CHA crystals with various Si/Al ratios were studied for gas adsorption. • The adsorption were performed in a wide temperature range of 150–350 K. • Single gas and CO 2 /CH 4 permeation were measured over an ultra-thin CHA membrane. • Adsorption parameters were used to model mass transport through the CHA membrane. • High CO 2 /CH 4 selectivity is mostly due to high surface permeability selectivity. [ABSTRACT FROM AUTHOR]

Moreover, the water-anion interactions can repel the contact of water with the active centers, thus inhibiting the occurrence of HER. The halogen anions can form hydrogen bonds with intermediates (*COOH) and thus lower the energy barrier to the formation of CO. Keywords: CO; CO2 Electrocatalysis; Covalent Organic Framework; Hydrogen Bond; Imidazolium EN CO CO2 Electrocatalysis Covalent Organic Framework Hydrogen Bond Imidazolium 1 1 1 02/07/23 20230206 NES 230206 B A hydrogen bonding strategy b for achieving an excellent electrocatalytic CO SB 2 sb reduction reaction performance over an imidazolium-functionalized covalent organic framework (Co-iBFBim-COF-X) is reported by Yuan-Biao Huang and co-workers in their Research Article (e202215687). [Extracted from the article]