Quantification of metal-acid balance in hydroisomerization catalysts: A step further toward catalyst design

Abstract : A methodology was developed to interpret the results of n-paraffins hydroisomerization over bifunctional catalysts based on two simple kinetic models used consecutively. Firstly, a macrokinetic model was used to obtain the corresponding turnover frequency over the acid sites and the maximum of C 16 isomer yield. Secondly, a dual-function model was used to correlate these catalytic descriptors to the ratio of metal to acid sites of the catalyst. To illustrate the methodology, Pt/HBEA and Pt/HUSY catalysts with different Pt loadings were evaluated. The impact of metal-acid balance on the catalytic turnover frequency and the maximal C 16 isomer yield were adequately captured for the bifunctional HUSY and HBEA catalysts. Moreover, the parameters of the dual-function model revealed to be intrinsic to the catalytic properties of the zeolite under the scope. This methodology is believed to be of interest for information-driven catalyst design for the hydroisomerization of n-paraffins.