Ecofriendly K-decorated ZnO/Zn(Al,La)2O4 catalyst for hydrogen production – Effect of heterostructure on catalyst activity at steam‐lean process gas

• Published in: Fuel (Guildford) Vol. 302; p. 121067
• Main Authors: Antoniak-Jurak, Katarzyna, Kowalik, Paweł, Próchniak, Wiesław, Bicki, Robert, Michalska, Kamila, Słowik, Grzegorz
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15-10-2021; Elsevier BV
• Subjects: Aluminum; Catalysts; Chromium; Copper; Decoration; heterostructure of ZnO-ZnAl2O4; Heterostructures; High temperature; Hydrogen; Hydrogen production; Layered double hydroxides; Memory effect; Mixed oxides; Morphology; Potassium; Potassium surface decorated spinel; Shift reaction; Steam; Water-gas shift; Zinc; Zinc oxide; heterostructure of ZnO-ZnAl2O4; Water-gas shift; Potassium surface decorated spinel; Hydrogen; Memory effect; Layered double hydroxides
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.121067

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•The effect of ZnAlLa-LDH calcinations temperature on HT-WGS activity of K-decorated ZnO/Zn(AlLa)2O4 mixed metal oxides.•Significant impact of heterostuctural surface morphology of mixed oxides on HT-WGS activity at lower steam/dry gas ratios.•High resistance of K-decorated ZnO/Zn(Al,La)2O4 catalyst against HT-WGS process conditions.
The effect of ZnAlLa-LDHs calcinations temperature on physicochemical and catalytic properties of K-decorated Zn-Al-La mixed oxides for water-gas shift reaction was investigated. The fresh and spent catalysts were characterized using various methods including XRF, N2 adsorption, TG/DTG/MS, XRD, FT-IR, STEM-EDS and HRTEM. Catalysts activity tests were carried out in high-temperature water-gas shift (HT-WGS) reaction in kinetic regime within the temperature range of 330–400 °C and H2O/dry gas molar ratio in the range of 0.5–1. The relationship between the structural, surface morphology of catalysts and the activity in the HT-WGS reaction was studied. The presence of ZnO-Zn(AlLa)2O4 heterostructure decorated with potassium species enhances HT-WGS activity. Calcinations of ZnAlLa-LDH precursor at mild conditions creates a favorable morphology of the surface and results in relatively high activity similar to the standard HT-WGS catalyst (Fe-Cr-Cu). The highest activity in the HT-WGS reaction at lower steam/dry gas ratios was obtained for the ZnAlLa_600_K.