Au/MnOx/3DOM La0.6Sr0.4MnO3: Highly Active Nanocatalysts for the Complete Oxidation of Toluene
Au/MnOx/3DOM La0.6Sr0.4MnO3: Highly Active Nanocatalysts for the Complete Oxidation of Toluene
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DOI：
10.1021/ie504304u
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发表时间：
2015-01
影响因子：
4.2
通讯作者：
Yang Jiang;Jiguang Deng;S. Xie;Huanggen Yang;H. Dai
中科院分区：
文献类型：
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作者：
Yang Jiang;Jiguang Deng;S. Xie;Huanggen Yang;H. Dai
采用原位聚甲基丙烯酸甲酯模板法和气泡辅助聚乙烯醇保护还原法制备了三维有序大孔La0.6Sr0.4MnO_3(3DOM-LSMO)负载的氧化锰和金(y=1.76-6.85wt%；z=8wt%(质量分数为Mn2O))纳米催化剂。3DOM LSMO载体具有菱面体晶体结构，比表面积为22~25m2/g，MnOx和Au纳米粒子(NPs)(3.2~3.8 nm)均匀分散在3DOM LSMO表面。结果表明，样品对甲苯氧化的催化性能与其表面吸附氧物种浓度和低温还原性能密切相关。在所制备的样品中，5.92Au/8MnOx/3DOM LSMO在空速为20000mL/(Gh)时表现最好，T50%和T90%(对应于甲苯转化率分别为50%和90%)分别为205和220°C。在YAu/8MnOx/3DOM LSMO催化剂上测得的表观活化能为52.8-68.5kJ/mol。
Three-dimensionally ordered macroporous La0.6Sr0.4MnO3 (3DOM LSMO) supported manganese oxide and gold (yAu/zMnOx/3DOM LSMO; y = 1.76–6.85 wt %; z = 8 wt % (weight percent of Mn2O3)) nanocatalysts were fabricated by means of in situ poly(methyl methacrylate)-templating and gas bubble-assisted poly(vinyl alcohol)-protected reduction methods. The 3DOM LSMO support possessed a rhombohedral crystal structure and a surface area of 22–25 m2/g. MnOx and Au nanoparticles (NPs) (3.2–3.8 nm) were well dispersed on the surface of 3DOM LSMO. Catalytic performance of the samples for toluene oxidation was found to be well related to their surface adsorbed oxygen species concentrations and low-temperature reducibility. Among the as-prepared samples, 5.92Au/8MnOx/3DOM LSMO performed the best at a space velocity of 20 000 mL/(g h): the T50% and T90% (corresponding to toluene conversion of 50 and 90%) were 205 and 220 °C, respectively. The apparent activation energies (52.8–68.5 kJ/mol) obtained over the yAu/8MnOx/3DOM LSMO...