Understanding structure-activity relationships of the highly active and stable La promoted Co/WC-AC catalyst for methane dry reforming

Dry reforming of methane (DRM) is an effective way to convert CH 4 and CO 2 into syngas. However, the activity and stability of the catalysts used need to be improved. Herein, the influence of the introduction of lanthanum on the catalytic performance of the Co/WC-AC catalyst for DRM was investigated. The catalysts were characterized by N 2 physical adsorption-desorption (BET), inductively coupled plasma emission spectroscopy (ICP), X-ray diffraction (XRD), Hydrogen temperature programmed reduction (H 2 -TPR), Temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS). BET and ICP analysis results confirmed that the added metals deposited on the outer and inner surface of the support. H 2 -TPR results show that the introduction of La reduces the interaction between the active ingredient and the support. The XRD results found that the introduction of La would inhibit the formation of CoWO 4 in the catalyst, thereby improving the activity of the catalyst. XPS characterization results showed that the added metal La can increase active components and the ratio of O α and O β in oxygen species, which is beneficial to catalytic performance. Among the catalysts, the 20Co–20La/AC-WC catalyst had the highest content of active components and the highest proportion of O α species, so it had better catalytic activity and stability. The maximum CH 4 conversion of 91.2%, CO 2 conversion of 90.7%, H 2 yield of 88.9% and H 2 /CO molar ratio of 0.9 are achieved at 800 °C. The addition of La not only inhibited the oxidation of WC species to WO 3 , but also had a better ability to resist carbon deposition during the reaction. Furthermore, La had a significant effect on the type of carbon deposits. • Effect of La addition on CH 4 dry reforming was investigated. • 20Co–20La/WC-AC Catalyst showed better activity and stability. • La can inhibit the formation of carbon on the catalyst surface. • The addition of La inhibited the oxidation of WC to generate CoWO 4 .