Effect of high-temperature coke deposition from methane upon the structure of manganese-yttrium oxides Original Research Article

Interaction of manganese-yttrium oxides with methane at 970 K can be viewed as proceeding in two consecutive steps: initial reduction of the system followed by formation of carbonaceous deposits due to CH4 decomposition. It was shown by SEM that methane degradation on Mn/Y2O3 systems resulted in vermicular and funnel-shaped carbonaceous deposits, as well as layered carbon. Upon carbonization, a substantial modification of oxide surface was observed by XRD and TEM; this included phase segregation and surface destruction with oxide species being torn off by growing carbonaceous deposits.