Synthesis and characterization of novel heterostructures for methane storage

Abstract

ABSTRACT: Methane constitutes up to 97% of natural gas. It is considered a sustainable alternative for liquid fuels (already in use). Its advantages are related with it low emission of carbon dioxide compared to other fossil fuels. It represents an emerging method, as an alternative fuel for vehicular applications. Its main drawback in mobile applications is to achieve an e cient, secure and economically acceptable storage. Conventional methods are based on the use of high-pressure storage tanks or cryogenic temperatures, which involve high costs due to the use of special materials. In order to avoid the aforementioned methods, investigations have been carried out related to porous materials, which are candidates for gas storage. Porous materials for methane storage include metal-organic lattices (MOFs), zeolites and a variety of carbon materials. This work refers to heterostructures (composite structures) based on nanotubes (MWCNT and SWCNT) and graphene oxide (GO) decorated with metal-organic structures (ZIF - 8, Cu - BTC and Fe - BTC), for its evaluation in methane storage. For the case of the Z8MW and Z8SW composites, these composites were obtained by synthesis by precipitation which is relatively simple and fast. Giving the formation of three-dimensional porous lattices that present micro and mesoporosity in a range of distributions between 2.1 to 40nm and a surface area between 800 to 1900m2 .g-1. For the case of the heterostructures of CuBTCMW and FeBTCMW, solvothermal route was employed. Unlike the composite structures CuBTCOG and FeBTCOG that were obtained by solvotermal synthesis. Structures with marked textural diferences are obtained from the super cal area (contact area) in a range of 700 to 1260m2 . g-1. The textural analysis of the starting MOFs in relation to their composite structures gives us information that not all carbon structures help the crystal growth of MOFs. Thesis main results are related with two accepted technological patents (another one in process). One manuscript and other two on desk preparation stage.