Low temperature activation of methane to hydrogen depending on tailored electron transfer over Ni–Cr composite oxide

Current industrial use of methane depends mainly on high-temperature conversion, resulting in high energy consumption and catalyst sintering inactivation. In this paper, metal oxide catalysts with different Ni/Cr ratios were obtained by the sol-gel method for the methane activation reaction. The structure-property relationships of the catalysts were investigated by XRD, XPS, H2-TPR, TG, N2 adsorption-desorption, and CV, focusing on the interaction between Ni–Cr in the composite oxide catalysts. The results showed that Ni0–NiCrO3/Cr2O3 structure was formed after the Ni–Cr oxides underwent the reduction and calcination process, which provided a structural support for electron transfer between the two metals. The least prone to sintering nickel metal particles and the highest content of high-valent chromium ions were present in Ni1Cr2. XPS confirmed that this counterpart acts as the donor and acceptor for electron transfer in the catalysts, accelerating oxidation-reduction reaction over the catalyst. The catalyst exhibited the most excellent conversion and product selectivity in the methane activation reaction.