Synthesis of mesoporous PrxZr1−xO2−δ solid solution with high thermal stability for catalytic soot oxidation

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2017, 54(0), , pp.126-136
• Main Authors: Li, Hongcheng, Li, Kongzhai, Zhu, Xing, Du, Yunpeng, Wei, Yonggang, Zhai, Kang, Wang, Hua
• Format: Article
• Language: English
• Subjects: Catalytic soot oxidation; Loose contact; Mesoporous oxides; Pr-Zr-O solid solution; Thermal stability; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2017.05.025

[Display omitted] In the present work, for the first time, we successfully prepared a series of mesoporous PrxZr1−xO2−δ solid solutions, which are used as catalysts for soot combustion. The obtained mesoporous materials possess BET surface area up to 139m2g−1 under the optimal condition. The aged catalysts (800°C for 3h) own enhanced activity for soot oxidation, indicating that the obtained materials possess excellent thermal stability under high-temperature treatment. •Mesoporous PrxZr1−xO2−δ solid solutions were prepared via a simple sol–gel method.•The anion of Zr precursor and template play the most important role for the formation of mesoporous structure.•Mesoporous structure can strongly improve the surface reducibility of PrxZr1−xO2−δ solid solution.•The catalytic activity is enhanced after high-temperature aging. The fabrication of mesoporous PrxZr1−xO2−δ solid solutions with different Pr/Zr molar ratios is reported in the present work. Based on a systematic investigation, the anion of Zr precursor and template species are found to play the most important roles for the formation of mesoporous structure. The triblock copolymer Pluronic F127 template helps to generate porosity in the matrix by self-assembly into micelle, while the additional Cl−1 from Zr precursor can lead to the enhancement of the interaction between non-ionic micelles. The physicochemical properties of the obtained samples were studied by means of N2 sorption analysis, TEM, XRD, H2-TPR, O2-TPD and XPS technique. It is found that, compared with the non-mesoporous counterparts, the mesoporous PrxZr1−xO2−δ solid solutions possess much higher specific surface area (139m2g−1) and enhanced redox ability. Also, the ability to release oxygen is improved after aging at high temperature. For the catalytic soot oxidation, the fresh mesoporous Pr0.1Zr0.9O2−δ catalyst (calcinated at 500°C) shows high activity in a loose contact condition (T50=399°C). It should be highlighted that the T50 values over the three mesoporous PrxZr1−xO2−δ samples decrease by 8–24°C after aging at 800°C for 3h. This suggests that the mesoporous PrxZr1−xO2−δ solid solution is an ideal candidate for catalytic application at high temperatures.