Electron-metal support interactions enhanced by W-O-Zr interface in Pd-UiO-66 catalyst for efficient HDO of lignin derivatives at room temperature

Electron-metal support interactions (EMSI), which can tailor the microenvironment through electron transfer and coordination structure design, are an effective strategy to augment the intrinsic catalytic activity of catalysts. However, it remains challenging to establish the interfacial structure and interfacial electron configuration of catalysts to precisely regulate and enhance EMSI. In this work, the spatially defective sites and specific electronic states of Pd-UiO-66 were modified by in-situ constructing a W-O-Zr interface to strengthen the EMSI between Pd nanoparticles (Pd NPs) and UiO-66 support via implanting W into the defective Pd-UiO-66, realizing the effective hydrodeoxygenation (HDO) of vanillin (VAN) at room temperature (RT). The as-prepared catalyst Pd-UiO-66–0.24 W achieved > 99 % conversion of VAN and > 99 % yield of 2-methoxy-4-methylphenol (MMP) within 12 h, which surpassed the previous reports. The DFT analysis revealed that the narrow band-gap energy between Pd-UiO-66–0.24 W and H 2 molecule, along with the σ or π coordination adsorption between p and d orbitals of the implanted W and O in C=O, facilitated the activation of the H 2 molecules and reactant molecules. In addition, the constructed electron-deficient W-O-Zr interfacial sites provided more acidic sites that favor the cleavage of C-O bonds, promoting the HDO process of VAN. This work provides important insights into the modulation of EMSI, structural defects and acidic sites of metal–organic frameworks (MOFs)-based catalysts for efficient HDO of lignin-derived oxygenated compounds.