Functionalized ceria–niobium supported nickel catalysts for gas phase semi-hydrogenation of phenylacetylene to styrene

Abstract

The presence of phenylacetylene (PA) in the styrene (ST) stream poisons the catalyst during polymerization reaction, increasing the operational cost. Preparation of low cost, and active hydrogenation catalysts that are...

Niobium Modification of CeO2 Tuning Electron Density of Nickel–Ceria Interfacial Sites for Enhanced CO2 Methanation

“…34-0394), respectively, are observed . Furthermore, the absence of a distinct Nb 2 O 5 peak in the XRD patterns indicates the successful formation of the Nb–Ce–O solid solution upon Nb addition, as supported by the results of EDX mapping. ,, Notably, no significant NiO peak is observed in the XRD patterns due to the low Ni loading and the uniform dispersion of NiO particles. , …”

“…11 Furthermore, the absence of a distinct Nb 2 O 5 peak in the XRD patterns indicates the successful formation of the Nb−Ce−O solid solution upon Nb addition, as supported by the results of EDX mapping. 40,42,43 Notably, no significant NiO peak is observed in the XRD patterns due to the low Ni loading and the uniform dispersion of NiO particles. 16,39 To gain insights into the reduction process of Ni species in the Ni/NbCe catalyst, hydrogen-programmed temperature reduction experiments (H 2 -TPR) were conducted on catalysts with different Nb doping levels, as shown in Figure 2b.…”

“…While both peaks for Ni/10NbCe shifted to lower values of 209.4 and 206.6 eV, respectively. This difference indicates that the Nb 5+ has been successfully incorporated into the CeO 2 lattice, resulting in the formation of a Nb–Ce–O solid solution, therefore changing the electronic state of the Nb element. , This results in an increase in the conduction band electron concentration within the carrier. Additionally, the interaction between Ni and NbCe enhances the electron transfer to the active sites on the NiCe surface, optimizing the electronic properties of the Ni cluster and Ni–Ce interface and thereby improving the CO 2 methanation activity of the catalyst. ,, Textural parameters were also determined by nitrogen physisorption (Figure S5).…”