Quantitative evaluation of coupling effects of pore structures and metal loadings on catalytic hydrogenation of tar model reactants over sulfided NiMo/γ-Al2O3 catalysts: Role of segmented catalytic active phase volumes

Currently, there is no easy-to-use method for determination of catalytic active phase volume (APV). Therefore, the current study designed a calculation method by defining APV (alpha -> beta nm) as the difference in pore volume (alpha -> beta nm) between the catalyst support and the catalyst (without taking fine structure of the catalyst into account for simplicity). This new method was successfully validated through regression analysis of 15 catalysts (R-2 > 0.97). Moreover, the couplings of pore structures and metal loadings on catalytic hydrogenation of reactants were quantitatively assessed based on the calculation of APV. The promotion or inhibition effect of one compound on hydrogenation of other compounds may also vary with the couplings of metal loading and pore structure, but it wasn't taken into account in this study. The key segmented APVs (SAPVs) in various pore sections for hydroconversion of reactants were determined using a stepwise linear regression model at the 95% confidence level. The findings showed that the SAPVs in the pores with a pore size of 5-10 nm and 10-20 nm were responsible for hydroconversion of quinoline and most of the aromatic compounds, respectively. The predicted key SAPVs were consistent with the experimental observations, which demonstrated availability of the proposed APV.