The pristine and Mg-substituted LaAlO₃ perovskites were synthesized by the citrate sol-gel method and employed as supports for Ni catalysts in CO₂ reforming of methane. The Mg/La molar ratio of 2/8 was determined as the optimal amount of Mg substitution in Ni/La_1-xMg_xAlO_3-δ catalysts. Compared with the Ni/LaAlO₃ catalyst, the Ni/La_0.8Mg_0.2AlO_2.9 catalyst exhibited enhanced initial activity and improved stability. Structural characterizations including N₂ sorption (N₂ sorption), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX) elemental mapping, thermogravimetry-differential scanning calorimetry (TG-DSC), CO₂ temperature-programmed desorption (CO₂-TPD), X-ray photoelectron spectroscopy (XPS) and H₂ temperature-programmed reduction (H₂-TPR) were performed to elucidate the effect of Mg partial substitution. It is revealed that much smaller Ni nanoparticles were formed with Mg partial substitution, which may explain the enhanced reforming activity. The improved stability over the Ni/La_0.8Mg_0.2AlO_2.9 catalyst was rationalized with better anti-coke and anti-sintering properties, which was closely related with surface basicity, oxygen vacancies and metal-support interactions. The present work demonstrates that perovskites with appropriate surface modification can serve as novel supports for the preparation of highly active catalysts.

通过柠檬酸溶胶-凝胶法合成了原始的和Mg取代的LaAlO ₃钙钛矿，并将其用作甲烷CO ₂重整中Ni催化剂的载体。确定Mg / La摩尔比为2/8，作为Ni / La _1-x Mg _x AlO3 _-δ催化剂中Mg取代的最佳量。与Ni / LaAlO ₃催化剂相比，Ni / La _0.8 Mg _0.2 AlO _2.9催化剂具有增强的初始活性和改善的稳定性。结构表征包括N ₂吸附（N ₂吸附），X射线衍射（XRD），透射电子显微镜（TEM），能量色散X射线光谱仪（EDX）元素标测，热重分析-差示扫描量热法（TG-DSC），CO _2程序升温脱附（CO ₂ -TPD），X射线光电子能谱（XPS）和H _2程序升温还原（H ₂ -TPR）来阐明Mg部分取代的影响。结果表明，形成了较小的Ni纳米颗粒，并被Mg部分取代，这可以解释重整活性的提高。与Ni / La _0.8 Mg _0.2 AlO _{2.9相比具有}更高的稳定性合理化的催化剂具有更好的抗焦化和抗烧结性能，这与表面碱度，氧空位和金属-载体相互作用密切相关。本工作表明具有适当表面改性的钙钛矿可以用作制备高活性催化剂的新型载体。