No abstract

Supporting Documents 1) Temperature Programmed Decomposition (TPD) of the Dried Cake of FC67 Oxygen Carriers The cake obtained after drying the filtered precipitates (in co-precipitation method) was subjected to a temperature ramp from 100-1000 o C (at a rate of 20 o C/min, in air) in TGA. The derivatives of mass change as a function of temperature are shown below.

No abstract

Carbon capture and storage (CCS) is increasingly being accepted as a necessary component of any effort to mitigate the impact of anthropogenic climate change, as it is both a relatively mature and easily implemented technology. High-temperature CO 2 absorption looping is a promising process that offers a much lower energy penalty than the current state of the art amine scrubbing techniques, but more effective materials are required for widespread implementation. This work describes the experimental characterisation and CO 2 absorption properties of several new ternary transition metal oxides predicted by high-throughput DFT screening. One material reported here, Li 5 SbO 5 , displays reversible CO 2 sorption, and maintains ∼72 % of its theoretical capacity out to 25 cycles. The results in this work are used to discuss major influences on CO 2 absorption capacity and rate, including the role of the crystal structure, the transition metal, the alkali or alkaline earth metal, and the competing roles of thermodynamics and kinetics. Notably, this work shows the extent and rate to which ternary metal oxides carbonate is driven primarily by the identity of the alkali or alkaline earth ion and the nature of the crystal structure, whereas the identity of the e transition ion carries little influence in the systems studied here.

Oxygen carriers are a class of materials, typically solid oxides, that can reversibly store and release oxygen for a variety of applications in energy and chemical processes, e.g. chemical looping combustion (CLC) and chemical looping air separation (CLAS). In recent years, growing interest in these materials have been focused on their use in chemical looping selective oxidations. A method for enhancing the oxygencarrying capacity of oxygen carriers for use in selective oxidations is presented. In this approach, one material that is selective and active in the reaction is deposited on the surface of a second material acting as a reservoir of oxygen and as a support. Here, the approach has been investigated using the selective combustion of hydrogen in the presence of ethylene, an important step in the oxidative dehydrogenation of ethane. Bismuth oxides, supported on a range of ceria-zirconia materials, were made into particulate oxygen carriers and studied for their activity, selectivity and oxygen-storage capacity. STEM-EDS imaging showed that the bismuth phase was spread uniformly over the surface of the nanocrystalline particles. XPS measurements indicated that the surface was enriched with bismuth oxide. It was found that the presence of ceria in the support supplied lattice oxygen additional to that provided by the bismuth oxide, without affecting the selectivity of bismuth oxide towards the combustion of H 2 . In other words, the surface chemistry was decoupled from the bulk properties of the support, thus simplifying the design and formulation of selective oxygen carriers. This demonstrates a readily-applicable generic approach for the design of oxygen carriers for selective oxidations.