National Research Tomsk State University, Prospekt Lenina, 36, 634050, Tomsk, Russia.
Vernadsky Institute of Geochemistry and Analytical Chemistry of Russian Academy of Sciences, Kosygina, 19, Moscow, 119991, Russia and I. E. Tamm Theory Department, Lebedev Physical Institute, Russian Academy of Sciences, Leninskii Prospekt, 53, Moscow, 119991, Russia.
Phys Chem Chem Phys. 2021 Jul 14;23(27):14889-14897. doi: 10.1039/d1cp01305j.
Pd-Bi nanoparticles show high efficiency in catalyzing gluconic acid production by the glucose oxidation reaction. Although this type of catalyst was studied for some time, the correlation between bismuth content and catalytic activity is still unclear. Moreover, there is little information on the principles of the formation of Pd-Bi nanoparticles. In this work, the relation between bismuth content and the activity and selectivity of the PdxBiy/Al2O3 catalyst in the glucose oxidation process was studied. The catalytic samples were prepared by co-impregnation of the alumina support utilizing the metal-organic precursors of Pd and Bi. The samples obtained were tested in the glucose oxidation reaction and were studied by transmission electron microscopy (TEM), X-ray fluorescence analysis, X-ray photoelectron spectroscopy (XPS), and BET adsorption. It has been found that the Pd3 : Bi1 atomic ratio grants the highest catalytic efficiency for the studied samples. To explain this, we predicted stable Pd-Bi nanoparticles using ab initio evolutionary algorithm USPEX. The calculations demonstrate that nanoparticles tend to form Pd(core)-Bi(shell) structures turning to a crown-jewel morphology at lower Bi concentration, thus exposing the active Pd centers while maintaining the promoting effect of Bi.
钯-铋纳米粒子在催化葡萄糖氧化反应生成葡萄糖酸方面表现出很高的效率。尽管这种类型的催化剂已经研究了一段时间，但铋含量与催化活性之间的关系仍不清楚。此外，关于钯-铋纳米粒子形成原理的信息也很少。在这项工作中，研究了钯-铋/氧化铝催化剂中铋含量与葡萄糖氧化过程中活性和选择性的关系。通过利用钯和铋的金属有机前体浸渍氧化铝载体来制备催化样品。通过透射电子显微镜 (TEM)、X 射线荧光分析、X 射线光电子能谱 (XPS) 和 BET 吸附对获得的样品进行了测试。研究发现，对于所研究的样品，Pd3:Bi1 的原子比赋予了最高的催化效率。为了解释这一点，我们使用基于第一性原理的进化算法 USPEX 预测了稳定的 Pd-Bi 纳米粒子。计算表明，纳米粒子倾向于形成 Pd（核）-Bi（壳）结构，在较低的 Bi 浓度下转变为冠冕珠宝形态，从而暴露活性 Pd 中心，同时保持 Bi 的促进作用。
