To investigate the morphology of hydrotalcites synthesized in flow and examine the effect of aging temperature on surface area and pore size distribution, nitrogen adsorption-desorption isotherms were obtained for all the samples under study. All samples exhibit type IV isotherm with an H3 hysteresis loop (ESI Figure ), which is consistent with the presence of a mesoporous solid. LDHs synthesized by conventional batch co-precipitation in our laboratory have relatively low surface areas of 27-110 m 2 g -1 with mean value of 73±28 m 2 g -1 . The BET surface areas of the flow synthesized hydrotalcites, reported in Table , are much higher, in the range of 80-150 m 2 g -1 . Such a direct comparison is, however, somewhat arbitrary, since SBET value of LDHs depends on the sample's chemical composition and its aging temperature, and as we argue here, on the method of synthesis: batch vs flow coprecipitation. As there are few reports that examine pore structure of uncalcined hydrotalcites, we systematically considered the effect of composition and aging temperature for the flow-synthesized materials.