ABSTRACT Nickel‐based catalysts have gained significant attention for their applications in hydrogen production and purification via water‐gas shift (WGS) reaction. The nickel‐oxides interaction is pivotal in optimizing the catalytic performance of WGS reaction. Herein, the well‐defined Ni/CeO 2 catalysts with specific rodlike and polyhedral morphologies were used to investigate the facet‐dependent catalytic behaviors in WGS reaction. The structural properties were determined using multiple techniques, indicating that Ni/CeO 2 (110) and Ni/CeO 2 (111) model catalysts were successfully constructed with similar textural features except for the exposed facets. Ni/CeO 2 (111) exhibited higher intrinsic activity than Ni/CeO 2 (110) for WGS reaction (73.7 vs 61 h −1 ). TPSR and kinetic data suggested that Ni/CeO 2 catalyzed WGS reaction via redox pathway with the CO adsorption/activation as the rate‐limiting step. XPS and CO‐DRIFTS results revealed that Ni/CeO 2 (111) possessed stronger electronic metal‐support interaction (EMSI) and superior reducibility than Ni/CeO 2 (110), resulting in the enhanced WGS activity. DFT calculations further elucidated the facet‐dependent EMSI effect on CO and H 2 O adsorption/activation, revealing that Ni/CeO 2 (111) exhibits stronger CO adsorption and a lower reaction energy barrier (0.9 eV) than Ni/CeO 2 (110) (1.56 eV) with comparable H 2 O dissociation barriers (0.39 vs 0.61 eV) on both surfaces. This work highlights the facet‐dependent EMSI as an efficient strategy to optimize the Ni‐catalyzed WGS reaction.
Li et al. (Fri,) studied this question.