Simultaneous Production of Hydrogen and Carbon Nanotubes via Methane Decomposition over Some Transition Metals Containing Catalysts

Abstract

Due to the depletion of fossil fuels and its adverse environmental impact as a result of its greenhouse gases (GHG) combustion products such as COX (CO and CO2) which are considered as the main reason for global warming effect and climate change. Recently, hydrogen has increasingly been considered as a promising and environmentally friendly energy source. Moreover, hydrogen is utilized in many processes in chemical, food, metallurgical, and pharmaceutical industry and it is also a valuable chemical in many reactions (e.g. refineries). Currently, the commercial production of hydrogen is essentially carried out by catalytic steam reforming of hydrocarbons such as natural gas and naphtha. The main drawback of this process is the exhaust emission of CO and CO2 with the produced hydrogen. Therefore, methane catalytic decomposition into COx-free hydrogen is considered as a promising environmental friendly and economic process. It is a fully green single step technology for producing hydrogen and highly valuable carbon nanomaterials. From a commercial and economical standpoint, CDM is a useful technology since it produces both pure H2 and carbon nano-structured materials such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs). The former is a clean fuel, which can be utilized directly in fuel cell and the later is highly valuable graphitized carbon material.