Mo promoting Ni-based catalysts confined by halloysite nanotubes for dry reforming of methane: Insight of coking and H2S poisoning resistance

Dry reforming of methane (DRM) shows promise for converting greenhouse gases into syngas but developing stable Ni-based catalysts resistant to sintering, coking, and H2S poisoning is challenging. We developed a highly effective catalyst by confining Mo-promoted Ni-based catalysts within halloysite nanotubes. Mo alloying with Ni inhibits Ni particles' migration out of the nanotubes, preventing the sintering of metals while decreasing the graphitic degree of carbon, which can balance the formation and removal of coke. Mo slows down H2S poisoning on Ni by adsorbing it competitively, maintaining a balance between carbon formation and removal even when H2S adsorbed on Mo hinders its role. With the inclusion of Mo, the rate of deactivation in the presence of H2S was reduced by half. Our research highlights the numerous advantages of Mo species and draws a correlation between carbon deposition and H2S poisoning, which offer new insights for designing efficient DRM catalysts.