Structure-Property Relations of Nickel and Cobalt Substituted Yttrium Aluminum Garnets as Catalyst Materials for Dry Reforming of Methane

Abstract

Nickel- and cobalt-substituted yttrium aluminum garnets (YAGs) were synthesized varying their stoichiometries and the details of the thermal treatment procedures at elevated temperatures. Ni and/or Co substitution into the framework of Y3Al5O12 was found to be feasible up to molar metal contents of 6 mol %. The synthesis conditions were optimized towards a compromise of high phase purity of the high-temperature phase of YAG, still maintaining sensible specific surface areas of the resulting catalyst materials. The two synthetic procedures evaluated in the study allow introduction of nickel and cobalt into the oxidic framework of the YAG oxide, from which under reducing conditions, both metals can be exsolved. The catalysts were studied in the catalytic dry reforming of methane under stoichiometric ratio of CO2/CH4 at atmospheric pressure. The catalytic results indicate that for the best candidate materials performance is stable and a syngas of the desired ratio nH2/nCO = 1 is formed. Trends were observed towards nickel being the catalytically more active metal compared to cobalt.