Ensemble Effect of the Nickel–Silica Interface Promotes the Water–Gas Shift Reaction

Abstract

Silica is commonly considered an inert support, and limited research has been concentrated on its role in constructing active metal− (hydr)oxide interfaces. Herein, we found that modifying the surface of nickel with silica will significantly promote its catalytic performance toward the water−gas shift reaction (WGSR), and the well-fabricated Ni np @PS(H450) exhibits a WGSR rate of up to 725 ± 7 μmol CO g cat −1 s −1 at 350 °C, which is at the highest level compared with previously reported Ni-based catalysts. Combining the experiment and theory, we demonstrated that Ni δ+ −O−SiO x interfaces divide the Ni surface into small domains consisting of contiguous Ni atoms. With the aid of an ensemble effect, the adsorption energies of CO, OH, and H can be tuned into appropriate ranges. Moreover, the Ni δ+ −O− SiO x interfaces also inhibit the formation of a dense NiO (or Ni(OH) 2 ) layer, thus endowing the catalyst with high stability. This study offers valuable insights into the catalytic mechanism linking Ni and silica, which can aid in the development of high-performance Ni-based catalysts.

Stabilized inverse Y2O3/Cu interfaces boost the performance of the reverse water–gas shift reaction

“…The positive valence metal species on the surface of the used catalysts may be closely related to the formation of interface structures. 32,36 The XPS results also indicated that there were still positive valence Cu species on the surface of the used catalysts. As shown in Fig.…”

“…5e). 32,36 Based on the above-mentioned results, the adsorption and activation capacity of the catalysts for reaction molecules were further explored. As shown in Fig.…”

Role of H2O in Catalytic Conversion of C1 Molecules

“…In summary, regardless of the reaction pathways, fundamental factors controlling water dissociation and subsequent conversion are closely related to the geometric and electronic structures of the oxide supports and metal components in WGS catalysts . Strong interactions between the metal species and the support may promote the formation of unique interfacial sites for optimizing the catalytic performance for the WGS reaction. ,,, …”