Curvature Arrhenius plot for estimation of Arrhenius parameters and adsorption enthalpies for a dual-site (bimolecular) reaction

The curvature in Arrhenius plot for nopol production was analyzed for a Langmuir-Hinshelwood-Houg en-Watson (LHHW) rate law obtained from a dual site (bimolecular) model with surface reaction as limiting step (r'(c) = k(sr)K(A)K(B)C(A)C(B)/ (1 + KACA + KBCB)(2), where A and B are beta-pinene and paraformaldehyde, respectively). Using simple mathematics, the rate law could be expressed in terms of E-a, Delta H-a(ds),A and Delta H-a(ds,B), that can be estimated using curvature Arrhenius plot. It was proposed a quadratic function depending on the differences of adsorption enthalpies and new parameters that fits the function In (1 + omega) = alpha(ln omega)(2) + b(ln omega) + c, where omega = KACA0/KBCB0. Thus, the curvature of the alternative empirical model is more pronounced with increases of vertical bar Delta H-a(ds),A - Delta H-a(ds,B)vertical bar and when the a parameter is maximum. A proposed routine was used for final calculations. For nopol synthesis, the E-a, k(0), Delta H-a(ds,A) and Delta H-ads(,B) parameters were 35.032 kJ mol(-1), 20229 mol g(-1) h(-1), -55.62 kJ mol(-1) and - 188.43 kJ mol(-1), respectively. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

The curvature in the Arrhenius plot for nopol production was analyzed using a dual site model, and a rate law was obtained. The rate law parameters were estimated using mathematical calculations based on the curvature of the Arrhenius plot. A proposed routine was used for final calculations, and the parameters for nopol synthesis were determined.