Hollow carbon sphere encapsulated Ni-Mo nanoreactor for lignin derivatives upgrading with enhanced catalytic performance

Herein, a novel nanoreactor composed of Ni-Mo nanoparticles embedded in hollow carbon spheres (Ni₁₀Mo₁/HCSs) is designed via a sacrificial template method. This three-dimensional open structure exhibits exceptional catalytic activity for vanillin of hydrodeoxygenation (HDO), achieving a 99 % yield of 2-methoxy-4-methylphenol (MMP) under mild conditions (150 °C, 1.0 MPa H₂, 3 h). Density functional theory (DFT) calculations show that the adsorption and dissociation energy of H₂ on the Ni (111) surface are −1.46 eV and −1.62 eV greater than −0.36 eV and −0.94 eV on the NiMo (111) surface, respectively. The adsorption energy of vanillin on the NiMo (111) surface reaches −3.71 eV, obviously higher than that on the Ni (111) surface (−3.37 eV). Characterization and the above DFT calculations results reveal that Mo incorporation forms a Ni-Mo alloy, creating synergistic effects between metallic Ni and alloy sites to enhance H₂ adsorption/dissociation and reactant activation. The hollow carbon framework (876.24 m²/g) ensures high metal dispersion (≈4.3 nm) and stability. The catalyst maintains strong activity over five cycles and demonstrates broad applicability to other lignin derivatives.