Insights into durable NiCo catalysts on β-SiC/CeZrO2 and γ-Al2O3/CeZrO2 advanced supports prepared from facile methods for CH4-CO2 dry reforming

This study explores CeZrO2 deposited over commercial beta-SiC, and a highly ordered 3D beta-SiC synthesised in the laboratory via electrophoretic deposition, as well as gamma-Al2O3 in order to prepare three types of dual support for NiCo bimetallic catalyst in CH4-CO2 dry reforming (DR). CeZrO2 was deposited over gamma-Al2O3 and beta-SiC by dry impregnation (DI), wet impregnation (WI) and 2-step deposition precipitation (DP). XRD analysis indicated that the constituents of the dual supports were retained after calcination, as well as before and after the DR reaction. CeZrO2 remained as a mixed oxide solid solution, whilst alumina formed spinel structures with Ni and Co before the catalysts were reduced in H-2 during the pretreatment step prior to the activity tests. During 550 h stability tests, WI, 2-step SICAT/CeZrO2 and 2-step gamma-Al2O3/CeZrO2 solids were identified as the most promising catalysts, maintaining high DR activities without deactivation. Notably, 2-step SiC(SICAT) and 2-step gamma-Al2O3/CeZrO2 samples recorded the highest yield (H-2 = 77%, CO = 90%; H-2 = 71%, CO = 81%), with a coke content of 7.7 and 0.6 wt.%, respectively. Carbon deposition for the former is high; contrarily, for WI SiC(SICAT) solid, it accumulated a lower amount of 2.6 wt.%. No agglomeration of CeZrO2 and NiCo phases was observed, evidencing excellent robustness and thermal resistance of these dual supports. (C) 2014 Elsevier B.V. All rights reserved.