Highly active Nd-promoted Ni@Al2O3 core-shell catalyst for steam reforming of acetic acid: Insights of the remarkable coke resistance

Abstract

Aiming at enhancing the coke resistance of Ni-based catalysts, the Nd-doped Ni@A2O3 core-shell catalysts were prepared and their catalytic performance was evaluated in the steam reforming of acetic acid (SRAA). The catalysts were characterized by BET, XRD, XRF, HRTEM, H2-TPR, NH3-TPD, and DTG. The catalytic performance was greatly enhanced by the incorporation of Nd, with decreased yields of CO, CH4, and acetone, increased yield of CO2, and remarkable carbon resistance. The decoking behavior of the spent catalyst was elucidated by H2O18-TSD. A low reaction temperature facilitates the formation of amorphous carbon, leading to catalyst deactivation. The decoking ability of the catalyst is greatly improved by the Nd incorporation but is also catalyzed by the exposed Ni surface. The Ni0.01Nd@Al catalyst greatly balanced the exposed Ni surface and the mobile lattice oxygen, showing the highest catalytic activity, lowest coke deposition, and superb decoking ability.