Objective  Tar-rich coals are valuable resources integrating coal, tar, and gas properties. Catalytic pyrolysis serves as a significant approach for achieving green and low-carbon development of tar-rich coals. However, the research and development of efficient and recyclable catalysts for the pyrolysis of tar-rich coals remains highly challenging.

Methods  With HZSM-5@SiO₂@MgFe₂O₄ (HSMF) as the raw material, this study prepared HZSM-5@SiO₂@MgFe₂O₄ (mHSMF) with a hierarchical porous structure using the hydrothermal method and alkali modification, followed by the preparation of cerium-modified mHSMF (5-CeO₂/mHSMF) using the precipitation method. Employing a fixed-bed reactor, this study investigated the regulatory effects of 5-CeO₂/mHSMF on the pyrolysis products of tar-rich coals from the Shenfu block, along with the anti-carbon deposition performance of 5-CeO₂/mHSMF.

Results and Conclusions The results indicate that the CeO₂-based modification of HSMF was conducive to the formation of a hierarchical porous structure comprising micropores and mesopores on the surface of HSMF. Through pyrolysis at 650°C in the N₂ atmosphere for 1 hr using 5-CeO₂/mHSMF as a catalyst, the coals exhibited a tar yield of 13.38%, equivalent to a tar yield of 176% in the Gray-King assay. Compared to the pyrolysis of raw coals, the catalytic pyrolysis exhibited increases in the aliphatic-hydrocarbon and benzene-compound contents in tar of 3.04% and 3.07%, respectively and an increase in the H₂ and CH₄ content in coal gas of 10.49%. Through CeO₂-based modification, the catalyst enhanced the anti-carbon deposition performance by 86.1%, with carbon deposits of merely 11.60 mg/g and tending to form a stable graphitized structure. Overall, 5-CeO₂/mHSMF manifests significant regulation of the distribution and composition of the products from the catalytic pyrolysis of coals in the Shenfu block, along with encouraging anti-carbon deposition performance and magnetic recyclability.