Autothermal Oxidative Dehydrogenation of Ethane on LaMnO3- and Pt-Based Monoliths: H2 and CO Addition

The autothermal oxidative dehydrogenation of ethane in short contact time reactors can be carried out with high ethylene yields on LaMnO3-based non-noble-metal catalysts. The performance of LaMnO3 honeycomb monoliths is evaluated in direct comparison with state-of-the-art Pt catalyst in an autothermal reactor configuration at varying external heating, N2 dilution, C2H6/O2 ratio, and total flow rate. LaMnO3 and Pt are also compared after the addition of a secondary fuel. Evidence is present that H2 and especially CO addition are the means of increasing ethylene selectivity above 80% on LaMnO3, as preferentially this is oxidized in place of ethane. The lower activity of Pt toward CO oxidation makes CO addition ineffective on such a catalyst.