M. Nkiawete, R. Vander Wal
Penn State University,
Keywords: thermo-catalytic decomposition of methane, carbon nanostructure, active sites, deposition rates
Summary:Thermo-catalytic decomposition (TCD) is well-suited for the generation of hydrogen from natural gas. In this decarbonization process for natural gas, high purity solid carbon is produced pre-combustion, with potential commercial uses including energy storage. TCD provides a pathway to the hydrogen economy and creates a bridge from fossil fuel to future renewable hydrogen energy systems. Thermo-catalytic decomposition (TCD) of natural gas is an attractive alternative for hydrogen production in relation to conventional steam reforming. In addition to generating clean hydrogen, TCD does not produce CO/CO2 by-products or consume water resources. In this study, a synthetic natural gas blend diluted in an argon carrier served as the initial feed. The test matrix encompassed a series of temperatures (900 – 1,100 ℃) and reaction durations (1 – 12 hrs.). TCD measurements were performed using a hot wall reactor and flat substrates of silicon and quartz. TCD rates were measured periodically by deposit thickness, using scanning electron microscopy (SEM). The nanostructure of the deposit was accessed using transmission electron microscopy (TEM) and Raman spectroscopy. At selected stages during TCD, samples were subjected to activated chemisorption in preparation of active site measurement. Active sites were quantified by X-ray photoelectron spectroscopy (XPS).