Nickel and cobalt salt‐modified zeolites enabling high‐efficiency pyrolysis of oil shale

Abstract Pyrolysis experiments coupled with kinetic analysis and GC–MS were used to assess how HZSM‐5, Ni‐modified HZSM‐5, and Ni and Co‐modified HZSM‐5 influence pyrolysis behavior, product distribution, and shale‐oil quality. The HZSM‐5 mass fraction in the feed was 2%–20%, and the optimal loading was 10 wt %. Thermogravimetric and kinetic results showed that all three catalysts accelerated pyrolysis, increased mass loss relative to non‐catalytic runs, and reduced the apparent activation energy. Decarboxylation and free‐radical pathways were strengthened, which lowered oxygenate yields while enriching aromatics and short‐chain hydrocarbons. The aromatic fraction rose by 2.75% with HZSM‐5, 4.27% with Ni‐modified HZSM‐5, and 8.2% with Ni and Co‐modified HZSM‐5. Relative to the blank, both the abundance and diversity of alkenes and alkanes increased. These patterns indicate that catalytic cracking of macromolecular organics into smaller fragments governed the main decomposition stage. In a laboratory tubular reactor, the introduction of each catalyst altered both product yields and composition, resulting in a lower oil yield but improved oil quality. The overall catalytic activity followed the order Ni and Co‐modified HZSM‐5 > Ni‐modified HZSM‐5 > HZSM‐5, consistent with the anticipated synergistic interaction between the introduced metal sites and the inherent acid functionality of the zeolite framework.