Abstract: Defect engineering holds significant promise for addressing the low conductivity and limited adsorption of reactant molecules in hydrogen generation catalysts. Herein, theoretical predictions based on the d-band center and electron localization function (ELF) calculations indicate that the introduction of Ce induces charge rearrangement, enhancing charge enrichment on Pt atoms. Inspired by these theoretical predictions, a series of PtCeO_x/CoNi-LDH catalysts were fabricated for efficient hydrogen generation. The experimental results indicate that introducing metal defects will induce lattice expansion in CeO_x doping, leading to the elongation of Pt-O bonds, which effectively reduces the bond energy of Pt-O bonds. The reduction in Pt-O bond energy facilitates the capture and adsorption of reactant molecules, thus exhibiting outstanding catalytic activity with a NaBH₄ hydrogen generation rate (HGR) of 8992 mL min^-1 g_cat^-1. Density functional theory (DFT) calculations show that the adsorption-free energy of the rate-determining step in the PtCeO_x/CoNi-LDH catalyst is ca. -3.59 eV, which is lower than the reaction barrier of PtO_x/CoNi-LDH (-3.25 eV). This indicates that the PtCeO_x/CoNi-LDH catalyst more effectively facilitates the formation of transition state intermediates. Guided by DFT predictions, the successful fabrication of high-efficiency PtCeO_x/CoNi-LDH catalysts establishes a strong foundation for the design and development of future hydrogen generation catalysts.

Key words: PtCeO_x/CoNi-LDH, Metal defects, NaBH₄ hydrolysis, Theoretical calculation, Catalytic mechanism