Holmium promoted yttria-zirconia supported Ni catalyst for H2 production via dry reforming of methane

Herein, a series of 5NixHo/YZr (x = 1, 2, 3, 4, 5 wt%) materials, never reported before, were tested in DRM reaction and characterized using several techniques like Nitrogen phys-isorption, X-ray diffraction, UV-vis and RAMAN spectroscopies, High Resolution Trans-mission Electron Microscopy, H2-Temperature Programmed Reduction, CO2-Temperature Programmed De-adsorption and Thermogravimetry. The incorporation of Yttria in the structure modifies pore sizes and stabilizes cubic Zirconia phases, whereas the addition of Ho as a promotor brings stable cubic zirconia, stable cubic holmium zirconium oxide phase and a wide range of reducible NiO-interacted species. In particular, an optimum Ho loading of 4 wt%, characterized by a minimum bandgap, strong suppression of RWGS reaction and maximum amount of reducible NiO-interacted species allows to achieve 84.1% H2 yield and 84.1% CO yield constantly over 420-min time on stream. The least basic sites availability over 5Ni5Ho/YZr results into inferior catalyst performance. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, a series of 5NixHo/YZr materials were tested and characterized. The results showed that the addition of yttria modified the pore sizes and stabilized cubic zirconia phases, while the addition of holmium brought stable cubic zirconia and a wide range of reducible species. The catalyst with 4 wt% holmium loading exhibited the best performance.