Chinese Journal of Magnetic Resonance ›› 2018, Vol. 35 ›› Issue (3): 269-279.doi: 10.11938/cjmr20182646

Previous Articles     Next Articles

Hydrogenation Reaction on Pd-Cu Bimetallic Catalysts: A Parahydrogen-Induced Polarization Study

WANG Wei-yu1,2, HU Han1,2, XU Jun1, DENG Feng1   

  1. 1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan(Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences), Wuhan 430071, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-05-11 Online:2018-09-05 Published:2018-08-28

Abstract: Hydrogenation reaction of propyne on Pd-Cu bimetallic catalysts was studied using the heterogeneous parahydrogen-induced polarization (PHIP) nuclear magnetic resonance (NMR) technique. Incipient-wetness impregnation and sequential impregnation were used to prepare Pd-Cu/SiO2 bimetallic catalysts with different composition and morphology. With the ALTADENA (Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment) method, it was observed that both the composition and morphology of the bimetallic catalysts had significant influence on the efficiency of PHIP. The catalysts with lower Pd/Cu atom ratio had lower activity but higher polarization efficiency. Compared to isometric impregnation method, the palladium atoms in the Pd-Cu/SiO2 catalyst synthesized with the sequential impregnation method mostly stayed on the surface of bimetallic nanoparticles, generating larger Pd ensembles and leading to higher catalytic activity and lower polarization efficiency.

Key words: parahydrogen-induced polarization (PHIP), bimetallic catalyst, propyne hydrogenation reaction, signal intensity enhancement, nuclear magnetic resonance (NMR)

CLC Number: