Leaching of palladium atoms from small cluster models during Heck reactions – An experimental and theoretical study

Catalysis Communications

Chun-Ran Chang¹  Notker Rösch²  Jun Li³  Alexander Genest⁴  Katharina Wussow⁵  Andrea Abram⁵  Klaus Köhler⁵ 

[1] Corresponding author.;Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing 100084, China;Institute of Materials Chemistry, Technische Universität Wien, Getreidemarkt 9/BC, A-1060 Vienna, Austria;Shaanxi Key Laboratory of Energy Chemical Process Intensification, School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, China;Technical University of Munich, Department of Chemistry, Lichtenbergstr. 4, and Catalysis Research Center, Ernst-Otto-Fischer-Str. 2, 85748 Garching, Germany;

关键词: Palladium leaching;    Heck reaction;    DFT calculations;    Solid-liquid interface;   

DOI  :  

来源: DOAJ

【 摘 要 】

Relevant parameters for the leaching of palladium atoms from small Pd clusters during Heck reactions of bromobenzene and styrene have been explored computationally and experimentally. With density functional theory calculations, we modeled reaction free energies for removing a Pd atom from a Pd6 model cluster and for forming Pd-ligand complexes. Oxidative addition of bromobenzene decreases the dissolution energy. Additional parameters and mechanisms, especially bromide ions render the leaching process notably exergonic. Model results exhibit the same trends as the targeted experiments where Pd leaching from supported catalysts (Pd/C, Pd/SiO2) was monitored as function of reaction temperature, time and components.

【 授权许可】

Unknown