封装型Ni基催化剂对煤焦油模型化合物催化转化的性能研究OA北大核心CSTPCD

In order to increase the content of light fractions in coal pyrolysis tar and regulate tar cracking products in a targeted manner,Ni-based catalysts(x Ni@HZSM-5,x is Ni content,mass fraction)were prepared by in situ encapsulation,and their catalytic conversion effects on tar model compounds:fluoranthene and pyrene were investigated.The results show that the difference of the x Ni@HZSM-5 conversion rates of two model compounds under N2 atmosphere is relatively small.Under H2 atmosphere,2.0Ni@HZSM-5 has the maximum conversion rates of fluoranthene and pyrene,which are 51.91%and 46.21%,respectively.And 2.0Ni@HZSM-5 has higher stability than 2.0Ni/HZSM-5(Ni mass fraction is 2.0%)prepared by impregnation method.The catalysts were analyzed and characterized by characterization methods such as X-ray diffraction(XRD),transmission electron microscope(TEM)and N2 adsorption/desorption,etc.The results show that 2.0Ni@HZSM-5 has larger specific surface area and pore volume than 2.0Ni/HZSM-5,and Ni is located inside the molecular sieve pores,which has higher activity and stability.The reaction paths of fluoranthene and pyrene during catalytic conversion were deduced by analyzing the conversion products of model compounds under different atmospheres.