Tuning Interfacial Electronic Properties of Palladium Oxide on Vacancy-Abundant Carbon Nitride for Low-Temperature Dehydrogenation

Hydrogen energy has the merits of high energy value and zero carbon emissions, but its practical application is hindered by the intensive energy input required for dehydrogenation of liquid hydrocarbons (170–300 °C). Herein, toward highly efficient dehydrogenation of saturated N-heterocycles, assembly of PdO on carbon vacancy-abundant carbon nitride skeleton derived from in situ Zr-doping was demonstrated to improve catalyst with superior performance under mild conditions. Electron paramagnetic resonance (EPR), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS) confirmed that the Zr-doped carbon nitride (Zr–C₃N₄) support showed a higher number of lone pair electrons and faster electron transfer rate compared with the parent. Strong interaction between PdO and the C₃N₄ skeleton was proved by the hydrogenation temperature-programmed reduction (H₂-TPR) and XPS. By efficiently turning the electronic properties of PdO by Zr–C₃N₄, in which the affinity influences the strength of the metal–support interactions and therefore PdO dispersion, the as-prepared prototype catalyst PdO/Zr–C₃N₄ was capable of achieving complete dehydrogenation of a series of saturated N-heterocycles at only 140 °C within 8 h, supassing the performance rendered by most of the catalytic systems reported so far. This work offers a promising pathway for energy-efficient and cost-effective hydrogen energy utilization under practical conditions.