Electronic Metal-Support Interaction to Modulate MoS₂-Supported Pd Nanoparticles for the Degradation of Organic Dyes

Electronic modulation of heterogeneous metal catalysts has been considered as an effective means to optimize their catalytic performance. Two-dimensional nanomaterials, typically used as the supporting substrates for anchoring the active metal nanoparticles, are well-known to profoundly influence the electronic structure of metals through interfacial electronic metal-support interaction (EMSI). However, the detailed investigation of EMSI for catalytic enhancement still remains obscure at the microscopic level. Herein, we propose to utilize MoS₂ nanosheets to modulate the electronic structure of Pd through EMSI and investigate the influence of "support effect" of MoS₂ on the catalytic activity of Pd utilizing degradation of methylene blue (MB) with the electron donor NaBH₄ as a simple model reaction. Mechanistic investigations reveal that the electron transfer from Pd to MoS₂ makes a highly electron-deficient Pd surface. During the target catalysis, this interfacial electronic structure makes the surface of Pd favor the adsorption of electron-rich reactants (for example, NaBH₄), accelerating the electron transfer from NaBH₄ to MB. Our finding promises an effective and facile strategy for catalyst design and sheds more insights into the structure-activity relationship of supported metal catalysts in general.