Insight into the efficient oxidation of methyl-ethyl-ketone over hierarchically micro-mesostructured Pt/K-(Al)SiO2 nanorod catalysts: Structure-activity relationships and mechanism
Insight into the efficient oxidation of methyl-ethyl-ketone over hierarchically micro-mesostructured Pt/K-(Al)SiO2 nanorod catalysts: Structure-activity relationships and mechanism
复制标题
深入探讨分级微介观结构 Pt/K-(Al)SiO2 纳米棒催化剂上甲乙酮的高效氧化：结构-活性关系和机制
DOI：
10.1016/j.apcatb.2017.12.007
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发表时间：
2018-06-15
影响因子：
22.1
通讯作者：
Shen, Zhenxing
中科院分区：
文献类型：
--
作者：
Jiang, Zeyu;He, Chi;Shen, Zhenxing
制备了具有规则纳米棒（Pt/KA-NRS）和球形纳米花（Pt/KA-SNFS）形貌的分级微介孔Pt/K-Al-SiO2催化剂。Al原子的存在使载体上的硅醇基团减少，生成了Bronsted酸中心，促进了Pt纳米粒子的分散，提高了催化剂的稳定性。钾原子平衡载体的负电荷并增强O-2迁移率。Pt/KA-NRS催化剂具有优良的低温活性、CO2选择性和MEK氧化稳定性。其中，0.27重量% Pt/KA-NRS仅在170 ℃（活化能低至37.22 kJ.mol（-1））下完全转化MEK，比文献中报道的其他典型Pt/Pd负载型催化剂低100 ℃以上。甲乙酮活化过程中的主要中间产物是丁二酮和2，3-丁二醇，它们通过醛和酸转化为H2O和CO2。Pt/KA-NRS具有良好的催化活性，这归因于其规则的形态、高的Pt含量和分散性、优异的MEK吸附能力和低温下优异的上级O-2/CO2脱附能力。
Hierarchically micro-mesostructured Pt/K-Al-SiO2 catalysts with regular nanorod (Pt/KA-NRS) and spherical nanoflower-like (Pt/KA-SNFS) morphologies were prepared. The existence of Al atoms generates Bronsted acid sites and reduces silanol groups over the supports, promoting the dispersion of Pt nanoparticles and stability of catalysts. Potassium atoms balance the negative charge of supports and enhance O-2 mobility. The Pt/KA-NRS catalysts exhibit unexceptionable low temperature activity, CO2 selectivity, and stability for MEK oxidation. Amongst, 0.27 wt.% Pt/KA-NRS completely converts MEK at just 170 degrees C (activation energy as low as 37.22 kJ.mol(-1)), more than 100 degrees C lower than other typical Pt/Pd supported catalysts reported in the literature. Diacetyl and 2,3-butandiol are the main intermediates during MEK activation, which convert into H2O and CO2 through aldehydes and acids. The excellent catalytic activity of Pt/KA-NRS is ascribed to their regular morphology, high Pt content and dispersion, excellent MEK adsorption capacity and superior O-2/CO2 desorption capability under low temperature.