Zr-based metal–organic frameworks drived Rh–Mn catalysts for highly selective CO hydrogenation to C2 oxygenates

Abstract

A series of Zr-based metal-organic frameworks (UiO-66) supported Rh–Mn catalysts with various metal loadings were prepared by using a co-impregnation method, and the catalytic activities were investigated for the direct synthesis of ethanol-based C2+ oxygenates from CO hydrogenation. The catalysts were comprehensively characterized by means of N2 sorption, XRD, TEM, XPS, H2-TPR, and DRIFT. The structural and textural properties of the catalysts show clearly that the overall framework structure of UiO-66 can be beneficial to the high dispersion of supported metals, but the synergistic effect of Rh and Mn would be influenced by the metal loading or Mn/Rh ratio. When the loadings of Rh and Mn reached 3 wt.% and 3 wt.%, the catalyst has the best catalytic activity with the highest yield of C2+ oxygenates of 200.1 g/(kg h), which can be attributed to the enhanced CO dissociation ability of Rh sites and weaker Rh−CO band strength.