Investigation of the Reduction/Oxidation Behavior of Cobalt Supported on Nano-ceria

The Effect of CeO2 Preparation Method on the Carbon Pathways in the Dry Reforming of Methane on Ni/CeO2 Studied by Transient Techniques

The present work discusses the effect of CeO2 synthesis method (thermal decomposition (TD), precipitation (PT), hydrothermal (HT), and sol-gel (SG)) on the carbon pathways of dry reforming of methane with carbon dioxide (DRM) applied at 750 °C over 5 wt% Ni/CeO2. In particular, specific transient and isotopic experiments (use of 13CO, 13CO2, and 18O2) were designed and conducted in an attempt at providing insights about the effect of support’s preparation method on the concentration (mg gcat−1), reactivity towards oxygen, and transient evolution rates (μmol gcat−1 s−1) of the inactive carbon formed under (i) CH4/He (methane decomposition), (ii) CO/He (reverse Boudouard reaction), and (iii) the copresence of the two (CH4/CO/He, use of 13CO). Moreover, important information regarding the relative contribution of CH4 and CO2 activation routes towards carbon formation under DRM reaction conditions was derived by using isotopically labelled 13CO2 in the feed gas stream. Of interest was also the amount, and the transient rate, of carbon removal via the participation of support’s labile active oxygen species.

Using Volatile Organic Compounds in Waste Streams as Fuel

To meet the environmental regulations, volatile organic compounds (VOC) in waste streams of various industries are thermally oxidized before being released to the atmosphere. This thermal oxidation process requires use of additional fuel and energy, has high operational costs and requires frequent maintenance. As an alternative, these VOCs can be considered as fuels themselves. Even without considering the energy used for the supplemental fuel such as natural gas, the enthalpy of the VOCs incinerated is not negligible. Hydrogen, a valuable energy carrier, can be produced from VOCs by reforming them. In this study, a system that can reform VOCs in the exhaust stream of paint finishing operations and use it to produce hydrogen that can be used in a fuel cell for power generation was designed. Steam reforming experiments were conducted on different VOCs using a 10 % Co/CeO2 catalyst. The effect of different functional groups and the chain length was examined. This study shows the potential of dilute VOCs in the waste stream of many industries if they can be recovered and used as a fuel effectively instead of being incinerated.

Impact of the synthesis parameters on the solid state properties and the CO oxidation performance of ceria nanoparticles

A direct quantitative correlation of surface-to-bulk (O_s/O_b) reducible oxygen of ceria nanoparticles (NPs) with catalytic activity was revealed.