Investigation of H2 production via an integrated pathway of consecutive CO oxidation and dry methane reforming in the presence of Co3O4@HNTs catalyst

Pristine Co3O4 and Co3O4-halloysite nanotubes (Co3O4@HNTs) composite were synthesized and characterized using XRD, HR-TEM, Raman, and ATR-FTIR. Then, the catalytic activity of these materials towards dry methane reforming (DMR) either, the direct or indirect pathways were analyzed, through either direct or indirect pathways. The analysis was focused on the influence of different parameters, such as temperature, solid-phase mixture, and feeding gas stream composition. Results showed that both materials have bifunctional catalytic behavior. First, they showed high selectivity towards CO oxidation instead of methane oxidation, and subsequently, these materials also participated in the reaction between CH4 and CO2 to produce H-2. The presence of oxygen in the gas stream, as well as the use of the halloysite as support, proved to be determining factors to prevent the formation of coke or metallic cobalt on the catalyst, which increases the H-2 production. Finally, the highest H-2 production was obtained using the Co3O4@HNTs composite under a gas stream composed of CH4/CO/O-2 at 650 degrees C.

Automated summary

The catalytic activity of pristine Co3O4 and Co3O4-halloysite nanotubes composite towards dry methane reforming was analyzed. Results showed that both materials have bifunctional catalytic behavior and the Co3O4-halloysite nanotubes composite exhibited the highest H2 production under specific conditions.