Amphiphilic Pd@micro-organohydrogels with controlled wettability for enhancing gas-liquid-solid triphasic catalytic performance

The wettability of catalyst plays an important role in regulating catalytic performance in heterogenous catalysis because the microenvironment around the catalytic sites directly determines the mass transfer process of reactants. Inspired by gas trapped on the surface of subaquatic spiders, amphiphilic micro-organohydrogels with tunable surface wettabilities were developed by anchoring various alkane chains onto a poly(2-(dimethylamino)ethyl methacrylate) (p(DMAEMA)) hydrophilic microgel network. Palladium nanoparticles (Pd NPs) were encapsulated in amphiphilic microgels (amphiphilic Pd@M) to catalyze hydrogenation reaction, achieving higher activities than pristine monohydrophilic Pd@M composite. The underwater oleophilicity and aerophilicity of Pd@M composites were quantified by oil/gas adhesion measurements and computational simulations. The higher amphiphilic catalytic activities are attributed to the formation of a gas-oil-solid reaction interface on the catalyst surfaces, allowing rapid transport of H2 and organic substrates through water to the Pd catalytic sites. Additionally, amphiphilic Pd@M composites also exhibit more superior catalytic performance in multi-substrates reaction.