Physicochemical and isomerization property of Pt/SAPO-11 catalysts promoted by rare earths

Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method.Bimetallic catalysts LaPt/SAPO-11 or CePt/SAPO-11 was prepared by sequential impregnation method.The catalysts were characterized by X-ray diffraction(XRD),nitrogen adsorption,temperature-programmed desorption of ammonia(NH3-TPD),and Fourier transform infrared spectroscopy(FT-IR) techniques.The results showed that with the addition of rare earths the BET surface areas,pore volume,the amount of Bronsted acid and the total acidity of catalysts decreased slightly.However,the additive addition could lead to an increase in the amount of Lewis acid.Meanwhile,the introduction of additive was feasible to promote the dispersity of Pt.In addition,the hydroisomerization of n-heptane over different catalysts was studied.Compared with Pt/SAPO-11,LaPt/SAPO-11 or CePt/SAPO-11 showed higher catalytic activity and yield of i-C7 due to its higher Pt dispersion.