Hierarchical pore modification of Ni-based Y zeolite to enhance the hydrofining of Dongming lignite liquefied oil for producing high-grade liquid fuel

The trade-off between catalyst morphology regulation and electronic structure of metal centers is crucial for achieving goals of heterogeneous catalysis. In this study, a Ni-based mesopore Y zeolite, Ni@MY, was developed by a combined modification strategy of bond blocking and deposition-precipitation, and used for the hydrofining of ethanol-soluble portion (ESP) derived from Dongming lignite ethanolysis. The results show that Ni@MY has excellent hierarchical pore structures and enhanced acidity. These properties effectively improve the electronic properties of metal active centers and the accessibility of medium/large molecules, thereby significantly enhancing the performance of aromatic ring hydrogenation and heteroatom removal. In addition, the synergistic transfer of active hydrogen, including H ··· H, δ+ H ··· H δ- , H + , and H · can be induced over Ni@MY, which effectively promotes the conversion of different aryl ethers into alkyl cyclanes. Analysis revealed that ESP is rich in alkanes, arenes, phenols, ketones, and esters, with aromatics accounting for up to 69.3%. After hydrofining, the refined oil contained 96.8% saturated hydrocarbons, among which cyclanes accounted for as much as 83.6%. Compared with conventional Ni@Y, Ni@MY has superior suitability for processing complex crude oils derived from lignite liquefaction for producing high-grade liquid fuels.