Different Agglomeration Processes Induced by the Varied Interaction of Fe–Fe Analogues with Differently Charged Surfactants

The catalytic activity of Prussian blue analogues (PBAs) is mainly tuned via the control of material sizes and morphologies. However, the shapes and sizes of many PBAs are difficult to control. In this work, a facile approach is demonstrated using differently charged surfactants to tune the catalytic activity of PBAs. Fe-Fe PBAs prepared with non-ionic P123, cationic cetyltrimethylammonium bromide, and anionic sodium dodecyl sulfate are chosen to study the effect of surfactant charges on the catalytic activity. The transesterification of propylene carbonate to dimethyl carbonate by methanol is selected as a model reaction. Owing to the different agglomeration processes of PB particles after modified with differently charged surfactants, significantly varied shapes and sizes were observed. Accordingly, the catalytic activity is greatly varied by adding surfactants. The different catalytic activities may arise from the different behaviors of agglomeration of PB particles after surfactant modification as well as the material size and shape changes. Besides, apparent activation energies for PBs adding different surfactants were derived. Finally, the agglomeration mechanism of PB particles in the presence of differently charged surfactants was proposed.