Synchronous Construction of Ni/CeO<sub>2</sub>/C with\nDouble Defects as a Dual Engine for Catalytic Refinement of Lignin\nOil Under Hydrogen-Free Condition

The\nambiguous structural defect types and sites of catalysts impede\nthe investigation of structure–activity relationships at the\natomic scale for catalytic transfer of hydrodeoxygenation of lignin\nand its derivatives. In this work, oxygen vacancies (O<sub>v</sub>) and carbon defects (C<sub>d</sub>) in Ni/CeO<sub>2</sub>/C catalysts\nwere constructed by an in situ calcination atmosphere-induced engraving\nstrategy. The dual defect embodied the chemical characteristics of\nheterogeneous frustrated Lewis pairs, and the synergy between O<sub>v</sub> and C<sub>d</sub> could effectively promote the adsorption\nand activation of isopropanol and the oxygen-containing substrate,\nwhich stimulated the production of more reactive H<sup>δ+</sup> and H<sup>δ−</sup>, anchored the methyl group. Efficient\nconversion of lignin oil was achieved without initial H<sub>2</sub> pressure, yielding 56% liquid product and 62.9% C<sub>6+</sub> cycloalkanol\nselectivity. The traditional hydrodeoxygenation was transformed into\na solid–liquid two-phase catalytic transfer hydrodeoxygenation,\nwhich enhanced the mass transfer. This study developed a catalytic\nsystem for catalytic transfer hydrodeoxygenation and offered insights\nfor the preparation of heterogeneous frustrated Lewis pairs.