Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (10): 141-148.doi: 10.19964/j.issn.1006-4990.2022-0306

• Catalytic Materials • Previous Articles     Next Articles

Effect of Ni on selective hydrodegenation of polyaromatic hydrocarbons of Pt/γ-Al2O3 catalyst

JIN Fengying1,2(),YU Haibin1,WANG Yaquan2,ZANG Jiazhong1,GUO Chunlei1,LIU Hang1,MA Mingchao1,ZHAO Xunzhi1,LIU Kailong1   

  1. 1. CenerTech Tianjin Chemical Research and Design Institute Co. , Ltd. , Tianjin 300131, China
    2. Institute of Chemical Engineering, Tianjin University
  • Received:2022-05-18 Online:2022-10-10 Published:2022-11-03

Abstract:

A series of Pt/γ-Al2O3 catalysts with different nickel loading were prepared successfully by impregnation method used chloroplatinic acid hexahydrate and nickel nitrate as Pt and Ni precursors,respectively.The samples were characterized via inductively coupled plasma-atomic emission spectrometry(ICP-AES),nitrogen physical adsorption,ammonia-temperature programmed desorption(NH3-TPD),hydrogen-temperature programmed reduction(H2-TPR),hydrogen-temperature programmed desorption(H2-TPD),hydrogen-oxygen titration stoichiometry(H2-O2).Using reformed C10+ heavy aromatics as raw materials,the effect of nickel introduction on the selective hydrogenation performance of polycyclic aromatic hydrocarbons(PAHs) of Pt/γ-Al2O3 catalyst was investigated in a 30 mL fixed bed device.The fixed bed evaluation results showed that with the increase of nickel content,the hydrogenation activity of PAHs and the selectivity of monocyclic aromatic hydrocarbons were increased firstly and then decreased,when 0.5%(mass fraction) nickel was introduced into 0.1Pt/γ-Al2O3 catalyst,the hydrogenation activity and selectivity of PAHs were the best.At the same time,the conversion rate of PAHs was about 75%,and the selectivity of monocyclic aromatic hydrocarbons was more than 98%.Combined with the characterization results of H2-TPR,H2-TPD and H2-O2 titration,it was analyzed that the main reason was that the introduction of a certain amount of nickel improved the dispersion of platinum.At the same time,due to the low hydrogenation activation energy of platinum,platinum migrated to non precious metal nickel through overflow activated hydrogen,which improved the hydrogenation performance of metal nickel.In addition,the existence of platinum could also prevent nickel from forming spinel structure and other inactive phases,promote the reduction of nickel oxide,and then improve the activity,selectivity and stability of the catalyst for the hydrogenation of PAHs.

Key words: nickel, Pt/γ-Al2O3, polyaromatic hydrocarbons, monoaromatic hydrocarbons, selective hydrogenation

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