The thesis is devoted to establishing systematic relationships in the cata lytic pyrolysis of biomass components on the surface of nanosized oxides (SiO 2 , γ Al 2 O 3 , CeO 2 , CeO 2 /SiO 2 , Al 2 O 3 /SiO 2 , TiO 2 /SiO 2 ). The study provides a physicochemical basis for the thermochemical conversion of the most common biomass types into high value added products and biofuels. Novel approaches for establishing the mechanisms of thermal catalytic reactions, in the unified reactivity scale (Taft/Hammett constants and reaction constants ρ /ρ **), are introduced and verified using the LFER principle and exp erimental kinetic data (maximum reaction rate T max , reaction order n , activation energy E ≠≠, pre exponential factor ν 0 , change in activation entropy dS ≠≠). Developed approaches are based on: (i) modified Taft/Hammett equations (lg(k/k o ρ ·Σσ=lg(B/2.3lgB) · Δ T m ax /T o max ) for calculating the reaction constants ρ/ρ **; (ii) linear "structure reactivity" correlations between kinetic and thermodynamic parameters (inductive and steric constants of Taft and Hammett (σ **, σ, E s*s*)); (iii)
semi empiric equation for the kine tic isotope effect calculation KIE=k/k o =10 lg(B/2.3lgB) · Δ T max /To max ). The suitability of the developed theoretical and experimental approaches for determining catalytic pyrolysis mechanisms was confirmed by studying a comprehensive reaction series of fatt y and cinnamic acids, coumarins, and aliphatic amines. Several thermal transformations that are important for industrial catalytic conversion of biomass have been demonstrated and studied (ketonization, ketenization, decarboxylation, dehydration, decarbony lation, deamination).
The structure of surface complexes was investigated, the stages of their thermal transformations and main products were identified, and the kinetic parameters of pyrolysis processes on the surface of nanosized oxides were calculated ( T max , n, E ≠≠, ν 0 , dS ≠≠). The experiments were performed using a series of aliphatic carboxylic acids; natural (cinnam ic , ferulic, c a ffe ic ) and synthetic cinnamic acids and coumarins;
aliphatic amines (linear, branched and alicyclic); polysaccharides (chitosa n, dextran, heparin); semi synthetic components of peptidoglycans. Sterically controlled "concert ed " mechanism for the ketonization reaction on the surface of CeO 2 /SiO 2 was proposed on the grounds of: (a) analysis of the kinetic parameters of a comprehensi veisoentropic reaction series of fatty acids (including isotopically labeled compounds); (b) strong correlation "structure reactivity" ( Е 126,84 3.096 ΣE s * (R 2 =0.9488)); (c) 45 inverinversese DDeuterium Kinetic Isotope Effecteuterium Kinetic Isotope Effect, KIE,, KIE, (0.0689 for C(0.0689 for C22DD44HH22CO), attributedCO), attributed to to the smaller atomic radius of deuterium compared to protium.the smaller atomic radius of deuterium compared to protium.
