Correlation between the as-grown carbon nano tubes and prolonged activity toward hydrogen production over Co–Mo/MgO

Abstract

Novel proposal for the developed highly graphitized multi-walled carbon nanotubes (MWCNTs) over Co–Mo/MgO which served as a secondary support toward hydrogen production from low-density polyethylene waste (PE) was presented using two-stage system. Doping of Co3O4 with MoO3 into MgO exposed extra dispersion function through MoO3 and Co, Mo and MgO mixed oxides as well as further distribution of the active cobalt nano particles over the well graphitized thinner MWCNTs. Both of fresh and used Co/MgO and CoMo/MgO catalysts were characterized by XRD, TPR, Raman, TEM and TGA. Furthermore, the concentrations of released hydrogen through the reaction period were detected via online gas chromatography within 150 min. It was found that Mo improved the overall catalyst reducibility to be easier and distributed the active species in different forms of mixed species. Moreover, the catalytic performance toward hydrogen production from low density polyethylene waste was jumped from 51% to 81% after Mo addition within the reaction end. Also, full catalytically action was noticed for CoMo/MgO toward whole the charged hydrocarbon gases from the first decomposition stage without any deactivation. Additionally, the developed multi-walled carbon nanotubes were highly graphitized and more homogenous rather than over Co/MgO which deposited less graphitized carbon nano fibers.