Dicarboxylic acids were prepared by the one-pot oxidative cleavage of cyclic alkenes with aqueous H₂O₂ by adsorbing dodecyltrimethylammonium phosphotungstate nanoparticles, and silica particles functionalized with octadecyl chains and sulfonic acid groups, C₁₈/C₃SO₃H, at the W/O interface. Na₂HPO₄ and [C₁₂]H₂PO₄ conditioned the interlocking and self-assembly of the particles, enhancing the catalytic selectivity, especially for cyclooctene.