Thermocatalytic partial oxidation of methane to syngas (H2, CO) production using Ni/La2O3 modified biomass fly ash supported catalyst

Abstract

In this work, the biomass fly ash (BFA) supported Ni/La2O3 catalyst was synthesized for the first time to produce syngas, a mixture of CO and H2 via the partial oxidation of methane (POM). The BFA support was modified using laboratory synthesized Ni/La2O3 through the wetness impregnation technique. The Ni/La2O3-BFA catalyst was characterized by several techniques to investigate its suitability for the POM reaction. The characterization results showed that the crystalline structure, better metal support interaction and enhanced thermal stability of Ni/La2O3-BFA make it suitable for the POM. The synthesized Ni/La2O3-BFA catalyst remained stable for 30 h on stream during POM at 850 °C. The addition of La2O3 promoter and active metal Ni to the BFA improved the CH4 conversion from 55% to 85% and enhanced the H2/CO ratio from 1.4 to 2.0 while maintaining a reactants stoichiometric ratio of (CH4:O2 = 2:1). The study of spent catalyst by using various techniques confirmed that the stable catalyst exhibited coke resistance in the POM even after 30 h time on stream. Thus, the performance of BFA supported Ni/La2O3 catalyst shows more potential for catalytic applications due to its suitable physiochemical properties as it is a combination of multiple oxides that synergistically participate in the reaction steps and increases syngas production. It also provides low-cost, abundant, greener, and waste based alternative to expensive metal oxide as supports for catalytic applications.