New Particle Size-Dependent Kinetic Model of the Water–Gas-Shift Reaction Using an Iron-Based Catalyst under Fischer – Tropsch Conditions

Abstract

The effect of nanoparticle size on the kinetics of the water–gas-shift (WGS) reaction using an iron based catalyst used in the Fischer – Tropsch synthesis (FTS) was studied in a continuous spinning basket reactor. A series of iron oxide particles with different particle sizes doped with copper and lanthanum was prepared as the catalyst. A new size-dependent kinetic model for the WGS reaction has been developed by a thermodynamic method. The kinetic parameters of the model were evaluated from experimental results for iron catalysts with different particle sizes. The results show that the parameters of the size-dependent model changed with temperature and particle size. The surface tension energy (σ) of the iron oxide catalyst and the size-independent activation energy for the WGS reaction was calculated from the experimental results. The size-independent activation energy for the WGS reaction is calculated as 4 kJ mol–1 based on haematite particles.