Role of HY Zeolite Mesopores in Hydrocracking of Heavy Oils

摘要

Two kinds of NiMo/HY catalysts, with and without mesopores, were prepared starting from two NaY zeolites with different Si/AI ratios. Both catalysts possessed similar properties arising from micropores because the catalysts had similar zeolitic framework structures. For both catalysts, most of the NiMo sulfides were dis- persed inside the micropores. The remaining NiMo sulfides, be- ing relatively large particles (3-10 nm), were located on the meso- pore surface for the NiMo/HY with mesopores, whereas for the NiMo/HY without mesopores, they were located on the external surface of zeolite particles. The catalytic activities were evaluated by the hydrocracking of tetralin and atmospheric residue. Both cat- alysts showed similar catalytic performance in the hydrocracking of tetralin, which diffused into the micropores. In the hydrocracking of atmospheric residue, however, NiMo/HY with mesopores was supe- rior to that without mesopores. These results revealed the important role of mesopores as active catalytic sites in the hydrocracking of heavy oils.