Ni和Ce前驱体对Ni-CeO2/SiO2催化剂的甲烷部分氧化制合成气性能的影响  

Effects of nickel and ceria precursors on the performance of Ni-CeO2/SiO2 catalysts for methane partial oxidation to syngas

作　　者：赵芝莹 郑芳芳 翁维正[1] 黄传敬[1] 万惠霖[1] ZHAO Zhiying;ZHENG Fangfang;WENG Weizheng;HUANG Chuanjing;WAN Huilin(State Key Laboratory of Physical Chemistry of Solid Surfaces,National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学化学化工学院,固体表面物理化学国家重点实验室,醇醚酯化工清洁生产国家工程实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2020年第4期483-491,共9页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(21473144,21872111);教育部创新研究团队项目(IRT_14R31)。

摘　　要：以不同Ni和Ce的化合物为前驱体、商品SiO2为载体,采用浸渍法制备了一系列Ni/SiO2、CeO2/SiO2和Ni-CeO2/SiO2催化剂,对CeO2在SiO2载体上的分散情况进行了表征,在此基础上进一步探究了不同前驱体制备的CeO2/SiO2对Ni物种的稳定情况以及Ni-CeO2/SiO2催化剂的甲烷部分氧化(POM)制合成气的反应性能.研究发现:以Ce(NO3)3或Ce(NO3)3添加柠檬酸制备的CeO2/SiO2催化剂的氢气程序升温还原(H2-TPR)谱图中均同时出现了表面CeO2和体相CeO2物种的还原峰,而以Ce(CH3 COO)3制备的CeO2/SiO2催化剂上则主要含表面CeO2物种.不同前驱体制备的1%Ni/SiO2(1%为质量分数,下同)催化剂的POM反应稳定性均较差.向1%Ni/SiO2中添加CeO2后,以硝酸盐或硝酸盐添加柠檬酸制备的1%Ni-10%CeO2/SiO2催化剂的POM反应稳定性均显著改善,且Ni物种的还原峰温均有所提高,说明相关催化剂上的CeO2与Ni物种之间存在较强的相互作用,可以较好地稳定催化剂上的Ni物种,防止其在反应条件下烧结.向以乙酸盐为前驱体制备的Ni/SiO2中添加CeO2后,1%Ni-10%CeO2/SiO2催化剂的POM反应稳定性有所下降,其原因可能是该催化剂上的CeO2与Ni物种之间的相互作用较弱,不利于稳定Ni物种.Ni/SiO2,CeO2/SiO2 and Ni-CeO2/SiO2 catalysts were prepared with an impregnation method using different Ni and Ce compounds as precursors and commercial SiO2 as a support.The dispersion of CeO2 on SiO2 support was characterized.On this basis,the effects of CeO2/SiO2 prepared by different precursors on the stability of Ni and the reaction performances of Ni-CeO2/SiO2 catalysts for methane partial oxidation to syngas were further investigated.The results showed that both surface and bulk reduction peaks of CeO2 were observed in the H 2 temperature program reduction(H2-TPR)profiles of the CeO2/SiO2 prepared with Ce(NO 3)3 or Ce(NO3)3+citric acid as precursors.However,only the reduction peak of surface CeO2 was seen in the catalysts prepared with Ce(CH3 COO)3.The methane partial oxidation reaction stability of 1%Ni/SiO2 catalysts prepared wtih above three precursors was quite poor.When adding CeO2 to 1%Ni/SiO2 catalysts,the methane partial oxidation reaction stability of the 1%Ni-10%CeO2/SiO2 catalysts prepared with Ce(NO 3)3 or Ce(NO3)3+citric acid achieved a considerable improvement,and the reduction peak of Ni species for the 1%Ni-10%CeO2/SiO2-NO3 and 1%Ni-10%CeO2/SiO2-CA catalysts shifts to higher temperatures as compared to the 1%Ni/SiO2-NO3 and 1%Ni/SiO2-CA catalysts.This means that there was a strong interaction between NiO and CeO2 in these two catalysts.Therefore,CeO2 could stabilize Ni species and prevent Ni from sintering under reaction conditions.But comparatively,the interaction between NiO and CeO2 in the 1%Ni-10%CeO2/SiO2-Ac catalyst was relatively weak.As a result,Ni species cannot be well stabilized by CeO2.And compared with 1%Ni/SiO2-Ac,the stability of 1%Ni-10%CeO2/SiO2-Ac catalyst for methane partial oxidation reaction decreased.

关 键 词：Ni-CeO2/SiO2 前驱体 甲烷部分氧化 合成气 

分 类 号：O643.361[理学—物理化学]