TiO2 nanoparticles vs. TiO2 nanowires as support in hydrogen peroxide direct synthesis: the influence of N and Au doping
TiO2 nanoparticles vs. TiO2 nanowires as support in hydrogen peroxide direct synthesis: the influence of N and Au doping
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DOI：
10.1039/c6ra24357f
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发表时间：
2016-01-01
期刊：
影响因子：
3.9
通讯作者：
Mikkola, Jyri-Pekka
中科院分区：
文献类型：
--
作者：
Gemo, Nicola;Menegazzo, Federica;Mikkola, Jyri-Pekka
考察了Pd/TiO 2催化剂在过氧化氢直接合成反应中的催化性能。使用的设备是一个高压，半间歇装置配备了一个特殊的注射系统。采用湿法浸渍法制备了不同性质TiO 2负载Pd（1wt%）催化剂。调查了三个方面：（a）载体的结构（纳米颗粒对纳米线）;（B）第二活性金属（Au）的添加;（c）载体的N掺杂的影响。采用XPS、TEM和XRD对样品进行了表征。与纳米TiO 2相比，纳米TiO 2负载型催化剂具有更高的H2 O2选择性和更高的转化频率（TOF）。加入Au的Pd-TiO 2纳米线催化剂提高了H2 O2的选择性，由于改变的颗粒尺寸和电子效应。这两种N掺杂的催化剂的版本产生了更高的过氧化氢的选择性比母体非掺杂的。合成过程是这一观察结果的来源：存在较大的平均Pd纳米颗粒，因此有利于形成H2 O2作为主要产物。
The performance of Pd on titania support were evaluated in the direct synthesis of hydrogen peroxide. The equipment used was a high pressure, semi-batch apparatus equipped with a special injection system. Pd (1 wt%) catalysts on TiO2 materials with different nature were prepared by wet impregnation method. Three aspects were investigated: (a) the structure of the support (nanoparticles vs. nanowires); (b) the addition of a second active metal (Au); (c) the influence of N-doping of the support. All samples were characterized by means of XPS, TEM and XRD analyses. TiO2 nanoparticle supported catalyst demonstrated higher H2O2 selectivity and higher turnover frequency (TOF) than the catalysts based on TiO2 nanowires. The addition of Au to the Pd TiO2 nanowire catalyst improved the H2O2 selectivity due to altered particle size and electronic effects. Both N-doped versions of the catalysts gave rise to higher H2O2 selectivity than the parent non-doped ones. The synthetic procedure was the source of this observation: larger mean Pd nanoparticles were present, thus favouring the formation of H2O2 as the primary product.