Dry reforming of methane (DRM) is one of the most promising route to produce syngas as it utilizes two abundantly available greenhouse gases, CH4 and CO2. Noble metal catalysts are very active and stable towards dry reforming but are very expensive for industrial application. Therefore, Nickel based catalysts, which are inexpensive, have been well studied for DRM but are very much susceptible to deactivation by coking and sintering at high temperatures. Thus, thermally stable Nickel based catalysts which can resist deactivation are the catalysts of our interest. Pyrochlores (chemical formula A2B2O7) are such thermally stable catalysts. In this study, we work on Ni and Sr doped Lanthanum Zirconate (La2Zr2O7) pyrochlore catalysts, LNZ3 (3wt% Ni doped in Zr site), LSNZ1 and LSNZ6 (1 wt% and 6wt% Ni doped in Zr site while Sr in La site). These catalysts were prepared by modified Pechini method. Fresh catalysts were analyzed using some spectroscopic and thermal characterizations for DRM. XRD showed base pyrochlore peaks and a perovskite phase was observed in LSNZ6 structure. XPS showed Ni to be present in a mixture of +2 and +3 states as expected on the surface. Surface concentration of Ni was found to be less compared to bulk from XPS and SEM-EDS analysis. TPR for the catalysts showed Ni to be having stronger interaction with the surface in LNZ3 compared to LSNZ6 and LSNZ1. An additional peak corresponding to perovskite phase was seen in LSNZ6 Catalysts were tested for DRM as a function of temperature which showed that LNZ3 was more active with LSNZ6 taking the next place. Long run stability reaction runs and post run characterizations for coke detection were also done.

Study of dry reforming of methane over nickel-based pyrochlore catalysts

2019 Spring National Meeting

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