Metal Nanoparticles Over Active Ionic-Conductive Supports for the Reverse Water Gas Shift Reaction

Title: Metal Nanoparticles Over Active Ionic-Conductive Supports for the Reverse Water Gas Shift Reaction
Authors: Einakchi, Raha
Date: 2016
Abstract: Increase in carbon dioxide emissions due to economic activity induce global warming. The strong increase in energy demand, mainly based on oil and coal, induces a rapid increase in CO2 in the atmosphere. Within Canada, the amount of human-produced carbon dioxide is considerable because a large portion of energy is supplied by burning of fossil fuels. The Reverse Water Gas Shift (RWGS) reaction is a promising catalytic process for the utilization and subsequent activation of carbon dioxide to carbon monoxide, which can be further converted into fuels such as gasoline. The current thesis studies the development of nano-catalytic systems for the RWGS reaction. Mono- and bi-metallic nanoparticles based on Cu, Fe, Ru and Pt were prepared using a polyol synthesis method. The catalytic performance of three different types of metal oxides (ionically conductive, mixed ionic-electronic conductive and non-conductive) was investigated for the RWGS reaction. Conductive metal oxides including samarium-doped ceria (SDC), ceria (CeO2), yttria-stabilized zirconia (YSZ) and iron III oxide (Fe2O3) were further used as the catalyst supports and the nanoparticles of Cu, Fe, CuxFe1-x (x = 50 and 95 at.%), Ru, Pt, Ru50Pt50 and RuxFe1-x (x = 80 and 90 at.%) were subsequently deposited on them. A stoichiometric mixture of H2 and CO2, i.e. H2/CO2 = 1, was used under atmospheric pressure in the temperature range of 300 - 600°C in order to evaluate the catalyst performance in terms of activity, stability and selectivity. Nanoparticles deposited on ceria-based supports (CeO2 and SDC) showed superior catalytic performance compared to other metal oxides. Among all the catalyst tested, 5 wt.% Ru50Pt50/CeO2 showed the highest CO yield and satisfactory stability for RWGS reaction. The second best catalytic systems were based on Ru90Fe10/CeO2 and Ru80Fe20/CeO2, which are more attractive from the practical point of view.
CollectionThèses, 2011 - // Theses, 2011 -