Deactivation Behavior of Supported Gold Palladium Nanoalloy Catalysts during the Selective Oxidation of Benzyl Alcohol in a Micropacked Bed Reactor
Deactivation Behavior of Supported Gold Palladium Nanoalloy Catalysts during the Selective Oxidation of Benzyl Alcohol in a Micropacked Bed Reactor
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DOI：
10.1021/acs.iecr.7b01159
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发表时间：
2017-06
影响因子：
4.2
通讯作者：
Noor Al-Rifai;Peter J. Miedziak;M. Morad;M. Sankar;C. Waldron;S. Cattaneo;E. Cao;Samuel Pattisson;D. Morgan;D. Bethell;G. Hutchings;A. Gavriilidis
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文献类型：
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作者：
Noor Al-Rifai;Peter J. Miedziak;M. Morad;M. Sankar;C. Waldron;S. Cattaneo;E. Cao;Samuel Pattisson;D. Morgan;D. Bethell;G. Hutchings;A. Gavriilidis
在硅玻璃微填充床反应器中，考察了高活性负载型Au-Pd催化剂对苯甲醇氧化的催化性能。研究了催化剂制备过程中Au-Pd组成和阴离子含量对催化剂失活的影响，发现催化剂配方中Cl-和Au的用量与失活速率之间存在一定的关系。虽然Au有助于提高对目标产物的选择性，而Cl-离子有助于形成均匀的1-2 nm纳米粒子，但一旦超过一定量，较高的Au和Cl2-将不利于催化剂的稳定性。在所研究的所有催化剂中，小的(1-2 nm)金属纳米颗粒的损失明显，伴随着团聚和形成更大的>；10 nm颗粒。用透射电子显微镜观察到了以形成无定形表面膜为特征的二次失活机理，并与催化剂上碳物种的检测有关。
Highly active, supported Au–Pd catalysts have been tested for catalyzing benzyl alcohol oxidation in a silicon-glass micropacked bed reactor. The effects of Au–Pd composition and anion content during catalyst preparation on catalyst deactivation were studied, and a relationship between the deactivation rate and the amount of Cl– and Au used in the catalyst formulation was found. While Au aids in enhancing the selectivity to the desired product and the Cl– ions help the formation of uniform 1–2 nm nanoparticles, higher amounts of Au and Cl– become detrimental to the catalyst stability once a certain amount is exceeded. Loss of small (1–2 nm) metal nanoparticles was evident in all catalysts studied, accompanied by agglomeration and the formation of larger >10 nm particles. A secondary deactivation mechanism characterized by the formation of an amorphous surface film was observed via transmission electron microscopy in catalysts with high Cl– and Au and was associated with the detection of carbon species on ...