铈镧比对CexNi0.5La0.5-xO系催化剂甘油氧化蒸汽重整制氢性能的影响

利用共沉淀法制备了CeO₂和La₂O₃复合载体的Ce_xNi_0.5La_0.5-xOO(CeNiLaO)系催化剂，在固定床反应器中考察其甘油氧化蒸汽重整制氢(OSRG)性能，并采用X射线衍射(XRD)、程序升温还原(H₂-TPR)、激光拉曼光谱(Raman)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等手段对催化剂进行表征分析。结果表明：La₂O₃能够有效地分散Ni颗粒，减弱Ni颗粒在反应过程中的烧结，CeO₂提供的晶格氧能够消除催化剂表面的积碳，同时La会部分进入Ce的晶格取代部分Ce⁴⁺造成晶格畸变，提高表面的氧空穴数。La₂O₃和CeO₂的共同作用有利于减弱Ni因为烧结和积碳引起的失活。在不同Ce/La摩尔比的催化剂中，Ce_0.4Ni_0.5La_0.1O表现出最好的催化活性，并且该催化剂在长达210 h的稳定性测试中，甘油的转化率都在95%以上，气相产物中的氢气浓度达50%。

CexNi0.5La0.5-xO Catalysts for Hydrogen Production by Oxidative Steam Reforming of Glycerol: Influence of the Ce-to-La Ratio

Ce_xNi_0.5La_0.5-xO (CeNiLaO) catalysts were synthesized using a Ce-La composite oxide as the carrier via co-precipitation. They were applied in the oxidative steamreforming of glycerol (OSRG) in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction (XRD), H₂-temperature-programmed reduction (H₂-TPR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Xray photoelectron spectroscopy (XPS). The results showed that La₂O₃ improved the dispersion of metallic Ni and suppressed the sintering of metallic Ni particles; the lattice oxygen of CeO₂ inhibited and eliminated carbon deposition on the surface of the catalysts; and the substitution of some La³⁺ for Ce⁴⁺ ions induced a distortion of the lattice. The synergy of La₂O₃ and CeO₂ lessened the deactivation caused by the sintering and coke deposition and improved the catalytic performance. Among the catalysts with different molar ratios of Ce to La, Ce_0.4Ni_0.5La_0.1O had the best catalytic activity. The conversion of glycerol remained above 95% after a 210 h stability test, while a gaseous reformate of about 50% hydrogen could be steadily produced.