【Frontiers in HaiChuan Technology】Dalian Institute of Chemical Physics develops a new type of intermetallic carbide for efficient catalysis of the selective hydrogenation of acetylene

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Dalian Institute of Chemical Physics develops new intermetallic carbide for efficient catalysis of selective hydrogenation of acetylene. Release date: 2024-11-20. Recently, a team led by Academician Zhang Tao, Researcher Wang Aiqin, and Associate Researcher Yang Bing from the Institute’s Catalysis and New Materials Research Center (Group 1500), in collaboration with Professor Gong Jinlong from Tianjin University, has developed a palladium-based intermetallic carbide that provides a new strategy for the efficient catalysis of selective hydrogenation of acetylene under conditions rich in ethylene. In their preliminary work, Zhang Tao’s team developed a series of in-situ characterization methods with high spatial and temporal resolution, thereby elucidating the dynamic evolution patterns of single-atom catalysts, the mechanisms underlying their reaction stability, as well as their dynamic transformation into nanoparticles (JACS, 2021) ； JACS，2022 ； JACS，2023 ； JACS，2024 ； Chem, 2022). Among them, palladium intermetallic compounds with isolated palladium metal sites show good potential for use in the selective hydrogenation of acetylene (ACS Catal., 2015) ； ACSCatal.，2016 ； ChemCatChem.，2024 ； Chin. J. Catal., 2024). However, in-situ carbonization of intermetallic compounds remains a challenge due to the stable structures of saturated coordination. In this work, the team utilized a syngas atmosphere to induce the process, introducing carbon monoxide to interfere with the initial alloying nucleation phase transformation, thereby achieving one-step zinc-carbon carburizing and producing a new intermetallic carbide phase (Pd3ZnCx). A series of in-situ electron microscopy and spectroscopic characterization techniques elucidated the dynamic alloying and carbiding processes, and it was found that the polycrystalline Pdt transition phase formed by low-temperature zinc-carbon co-deposition serves as a key intermediate that promotes the infiltration of interstitial carbon and the formation of Pd3ZnCx intermetallic carbides. Performance tests show that Pd3ZnCx exhibits high activity, high selectivity, and excellent stability in the selective hydrogenation of acetylene ； High ethylene selectivity (>90 %) can still be maintained under reaction conditions with a high hydrogen to acetylene ratio. Theoretical calculation results indicate that the lower reaction rate-limiting step on the electron-rich Pd3ZnCx, the energy barrier for hydrogen dissociation, and the spontaneous desorption of the product ethylene are the main reasons for its excellent acetylene hydrogenation performance. The relevant research findings were published recently in Nature Communications under the title “Co-infiltration and dynamic formation of Pd3ZnC*intermetallic carbide by syngas boosting selective hydrogenation of acetylene”. The co-first authors of this work are Chen Huan, a doctoral student in Group 1502, and Li Lulu, a doctoral student at Tianjin University. The above work was supported by projects such as the **Key Research and Development Program**, the Basic Science Center for \"Single-Atom Catalysis\" of the National Natural Science Foundation of China, and the **National Natural Science Foundation**.