Highly reactive Ni-Co/SiO2 bimetallic catalyst via complexation with oleylamine/oleic acid organic pair for dry reforming of methane

Ni-Co alloy supported on silica is prepared with oleylamine/oleic acid (OAm/OAc) organic pair by incipient wetness impregnation (IWI) method. The alloy formation is confirmed by XRD, TEM, EDX, TPR and XPS and the homogeneous alloy is proved by TEM-EDX (line, mapping and point ID). Compared with monometallic catalysts, in the Ni-Co alloy, the Ni metal size is controlled by the Co addition; also, the Ni-silica interaction is strengthened by the strong interaction between Co and silica; moreover, Ni sintering and oxidation are prevented by the electron transfer from Co. On the other hand, compared with the alloy prepared with single ligand (OAm or OAc), the Ni-Co alloy prepared with the combination of OAm and OAc is homogeneously distributed. This small, highly dispersed, homogeneous Ni-Co alloy strongly interacting with silica support leads to a high conversion of CO2 and CH4 which maintains stable over 30 h dry reforming of methane (DRM) reaction without carbon deposition or metal sintering.