Syngas production via CO2 reforming of methane over Ni-Co-Mg-Al-La catalysts derived from hydrotalcite precursors prepared by ultrasound-assisted co-precipitation method

Dry reforming of methane (DRM) is a promising route for syngas production, especially over nanostructured catalysts. This study reports the synthesis of Ni-Co-Mg-Al-La mixed oxides derived from layered double hydroxides (LDHs) by two methods, conventional co-precipitation and a modified approach involving ultrasonic irradiation (US). The different compositions were characterized by XRD, TG/DTA, N2 adsorption-desorption, and SEM-EDX techniques. XRD and DTA results confirm that ultrasonic irradiation promotes the incorporation of lanthanum ions into the lamellar structure. Moreover, the specific surface areas of samples increase by 25% in the US. Due to the enhancement of physicochemical properties, catalysts prepared using ultrasound exhibited improved catalytic activity, with a 5.5% increase in CO2 conversion and a 4.7% increase in CH4 conversion. The characterization of spent catalysts (XRD, TG/DTA, SEM) revealed minimal carbon formation in the catalysts prepared with ultrasonic irradiation, demonstrating the promoting effect of sonication on the stability of catalysts against carbon deposition.