The objective of this work is to present formic acid as a suitable compound to be used in a hydrogen economy. Catalytic decomposition of formic acid at mild conditions is evaluated as a model reaction for hydrogen generation, making emphasis on the productivity, reusability of the catalysts, and quantification of concomitant CO evolved from the reaction. Characterisation of the fresh and used catalysts is performed to study the activity/structure relationship and investigate the possible reasons for its deactivation. Computational calculations are used to support experimental data and correlate productivity and CO evolution with the elementary steps of the reaction and the most common surfaces of the catalyst. Synthesis of materials with different surface properties and preparation methods is a fundamental part of this work. In Chapter 3, a commercial Pd/C catalyst is used as a reference to establish the reaction conditions that lead to a kinetically limited reaction. Reusability tests and subsequent characterisation of the used catalyst in conjunction with computational studies are performed to investigate its stability. Continuous flow experiments are carried out as a preliminary test to improve the reusability. Following the identification of the main parameters and characteristics of the catalysts involved in formic acid decomposition, in Chapter 4, materials with different properties (graphitisation degree and acid/base surface functionalisation) are synthesised by two preparation methods (sol-immobilisation and impregnation) using carbon nanofibers as supports. Once the optimal preparation method is identified, a set of parameters are modified in Chapter 5 to investigate the effects it has on the structure and morphology of the catalysts. Besides this optimisation, two supports (activated charcoal and titania) are investigated and an initial study of bimetallic catalysts and its properties is explored. Chapter 6 presents the main consequences of these results and a set of possibilities to continue this research.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:761368 |
| Date | January 2018 |
| Creators | Sanchez Trujillo, Felipe Juan |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/117629/ |
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