Catalytic Performance of Ni/CeO2/X-ZrO2 (X = Ca, Y) Catalysts in the Aqueous-Phase Reforming of Methanol

Abstract

In this study, we reported on the effect of promoting Ni/ZrO2 catalysts with Ce, Ca (two different loadings), and Y for the aqueous-phase reforming (APR) of methanol. We mainly focused on the effect of the redox properties of ceria and the basicity provided by calcium or yttrium on the activity and selectivity of Ni in this reaction. A systematic characterization of the catalysts was performed using complementary methods such as XRD, XPS, TPR, CO2-TPD, H2 chemisorption, HAADF-STEM, and EDS-STEM. Our results reveal that the improvement in reducibility derived from the incorporation of Ce did not have a positive impact on catalytic behaviour thus contrasting with the results reported in the literature for other Ce-based catalytic compositions. On the contrary, the available Ni-metallic surface and the presence of weak basic sites derived from Ca incorporation seem to play a major role on the catalytic performance for APR of methanol. The best performance was found for a Ce-free catalyst with a molar Ca content of 4%.

Enhancing the CO2 methanation activity of Ni/CeO2 via activation treatment-determined metal-support interaction

“…The a peak with a temperature maxima (T max ) at 445 K was clearly observed over the sample treated in air (Ni/ CeO 2 -Air) that can be assigned to reduction of weakly adsorbed surface oxygen species [17,40]. The b peaks (T max = 490 K), recorded over all the catalysts can be ascribed to the reduction of highly dispersed surface NiO species [40][41][42]. We can note that Ni/CeO 2 -H 2 shows larger hydrogen consumption associated with the b peak than that for Ni/CeO 2 -N 2 and Ni/CeO 2 -Air, suggesting a greater number of highly dispersed surface Ni species were formed.…”

“…We should note that the b signal with regard to Ni/CeO 2 -H 2 is linked to facile oxidation of highly dispersed Ni phase when exposed to air, although the sample was thermally treated in H 2 prior to TPR. The c hydrogen consumption signal (T max = 555 K), observed over Ni/CeO 2 -Air, has been assigned to the reduction of bulky NiO particles interacting strongly with CeO 2 [40][41][42][43]. The c signal of Ni/CeO 2 -N 2 migrated to a higher temperature (T max = 570-K), which suggests the decomposition of the nickel precursor generated larger NiO particles.…”

IR Reflective LaPO4 Ceramic Colorant Reinforced Polymer Composite Coatings on Glass and Metal Substrates for Heat Management Applications

“…The binding energies due to La3d 5/2 and P2p 3/2 shifted slightly towards a lower value in comparison with the XPS data of LaPO 4 indicated the change in chemical environment due to the presence of Ni 2+ . During the synthesis of green colorant via solid state reaction, the NiO undergoes partial decomposition to Ni and occupies at the lattice position of La 3+ there by results with the respective binding energy peak at 852.9 eV [17,19] . The remaining NiO diffuses into the bulk which was evident with a peak generated at 855.8 eV due to Ni 2+ .…”

“…During the synthesis of green colorant via solid state reaction, the NiO undergoes partial decomposition to Ni and occupies at the lattice position of La 3 + there by results with the respective binding energy peak at 852.9 eV. [17,19] The remaining NiO diffuses into the bulk which was evident with a peak generated at 855.8 eV due to Ni 2 + . As a result of this substitution, the chemical environment of the rare earth matrix changes and a corresponding shift in the binding energies of La and P were observed.…”

Application of New Nanoparticle Structures as Catalysts

“…In the case of the contribution by Cauqui et al [ 5 ], a mixed oxide (ZrO 2 with different loadings of Ce, Ca and Y) is used as a support of Ni nanoparticles. In this study, the synthesized nanomaterials are extensively characterized by complementary methods and techniques, and evaluated as catalysts for the aqueous-phase reforming of methanol.…”