This study involved the preparation of a biochar-based nano‑nickel (Ni/C) catalyst, achieving high dispersion of the nano‑nickel catalyst by utilizing waste coffee grounds as a biochar carrier. The Ni/C catalyst demonstrated commendable catalytic performance in heavy crude oil upgrading. Compared with the control group, the viscosity reduction rate of heavy crude oil was increased by 21.53 %, and the contents of heteroatoms, resins and asphaltenes were effectively reduced, while increasing the ratio of C2-C4 and saturated components. Additionally, the catalyst reduced the initial decomposition temperature and the maximum thermal decomposition rate temperature of oil shale by 10 °C and 8 °C, respectively. The results of DFT calculations also indicated that the catalyst effectively improved the pyrolysis activity of kerogen molecules. Noteworthy characteristics of the catalyst include its low cost, simple operation, and high catalytic activity, making it highly promising for broad applications in unconventional petroleum energy exploitation.
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