Easy synthesis of three-dimensionally ordered macroporous La₁₋ₓKₓCoO₃ catalysts and their high activities for the catalytic combustion of soot

• Published in: Journal of catalysis Vol. 282; no. 1; pp. 1 - 12
• Main Authors: Xu, Junfeng, Liu, Jian, Zhao, Zhen, Xu, Chunming, Zheng, Jianxiong, Duan, Aijun, Jiang, Guiyuan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 15.08.2011; Elsevier
• Subjects: active sites; carbon; Catalysis; catalysts; catalytic activity; Chemistry; Colloidal state and disperse state; combustion; energy-dispersive X-ray analysis; Exact sciences and technology; Fourier transform infrared spectroscopy; General and physical chemistry; hydrogen; polymers; Porous materials; scanning electron microscopy; soot; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; titration; transmission electron microscopy; X-ray diffraction; X-ray photoelectron spectroscopy; Amorphous material; CoO; Perovskite type compound; In situ; Active site; Soot; Oxides; X ray; Carboxy-modified colloidal crystal; K; Density; Porous material; Three-dimensionally ordered macroporous; Template; Pore size; Catalytic combustion; Synthesis; La; catalysts; Photoelectron spectrometry; Oxidation; Macrostructure; Differential scanning calorimetry; Scanning electron microscopy; Catalytic reaction; Crystals; Polymer; Carbon; X ray diffraction; Infrared spectrometry; Inert atmosphere; Heterogeneous catalysis; Transmission electron microscopy; templating method; Preparation; Frequency; Catalyst; Macroporosity
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2011.03.024

Three-dimensionally ordered macroporous (3DOM) La₁₋ ₓKₓCoO₃ (x=0–0.3) perovskite-type oxide catalysts with large pore sizes and interconnected macroporous frameworks were successfully synthesized by a novel method of carboxy-modified colloidal crystal templates (CMCCT). The obtained catalysts were characterized by means of XRD, FT-IR, SEM, TEM, BET, XPS, and H₂ TPR. The detailed preparation process was investigated using in situ TG–DSC, Raman, and EDS analyses. The sp²-hybridized carbon atoms of the modified polymer templates can be converted to sturdy amorphous carbon materials by calcination under an inert atmosphere to prevent the macrostructure from collapsing. The active site densities of catalysts were determined by isothermal anaerobic titration, and their turnover frequency (TOF) values were then calculated. The catalytic performances for soot combustion were evaluated using temperature-programmed oxidation (TPO) reaction technology. 3DOM La₁₋ ₓKₓCoO₃ catalysts exhibited catalytic activities as high as that of noble metal Pt catalysts under loose contact conditions.