Nanostructured transition metal carbides as potential catalysts for greenhouse gases conversion
[eng] Over the recent decades, several studies revealed the precarious climate situation which is threatening all Life forms on earth, including mankind, even if sometimes we tend to ignore the actual fragility of our situation. Ironically, the human species is at the origin of the rapid change on c...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2021 |
| Country: | España |
| Institution: | Universidad de Barcelona |
| Repository: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/181967 |
| Online Access: | https://hdl.handle.net/2445/181967 http://hdl.handle.net/10803/673020 |
| Access Level: | Open access |
| Keyword: | Catàlisi heterogènia Nanopartícules Gasos d'efecte hivernacle Carburs Heterogeneus catalysis Nanoparticles Greenhouse gase Carbides |
| Summary: | [eng] Over the recent decades, several studies revealed the precarious climate situation which is threatening all Life forms on earth, including mankind, even if sometimes we tend to ignore the actual fragility of our situation. Ironically, the human species is at the origin of the rapid change on climate, mostly by practicing unsustainable activities, such as the unregulated consumption of fossil fuels, excessive deforestation, extensive agriculture, and intensive livestock. All these practices have increased the concentration of greenhouse gases in the atmosphere, producing a rapid increase in the average Earth temperature with noticeable consequences in our lifetime. Nevertheless, several efforts have been conducted by the scientific community in order to revert the actual climate situation, even if society acts delayed. One of the actual work routes implies the use of catalysts to capture and convert greenhouse gases into less harmful and more useful chemicals. This route has found in transition metal carbides (TMCs) proficient candidates that could have an important impact in the aforementioned matter. An interesting aspect of TMCs is their capacity to catalyse such transformation reactions at low temperatures and to withstand several reaction cycles without degrading. Precisely, the present Thesis unveils and discusses several reaction mechanisms involved in the greenhouse gases transformation reactions held by TMCs, particularly, focusing on MoCy nanoparticles, a largely unexplored field. This Thesis combines experimental and theoretical approaches to explain the observed experimental evidences, where custom synthetized MoC nanoparticle supported on Au(111) are able to activate methane at room temperature, hydrogenate CO2, and act as superior H2 sponges with respect to clean MoC extended surfaces. Moreover, other important findings are revealed, such as the reconstruction held by some transition metal carbides and nitrides surfaces and the intrinsic nature of clean MoC nanoparticles towards hydrogenation reactions. Overall, the present dissertation intends to encourage further efforts on developing TMC based catalyst able to be used at industrial levels. The experimental section of this thesis has been carried out at the Brookhaven National Laboratory by the group of Prof. J. A. Rodriguez, while the computational part and results analysis has been carried out in the present institution, the Universitat de Barcelona. The results obtained have led to several joint publications. |
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