(544ce) Adding Water to the Feed of Formic Acid Decomposition over ?-MoC Catalyst on Graphite

Authors: 
Aldoshan, Y., Washington State University
Ha, S., Washington State University
Gray, J. T., Washington State University

Electric field assisted catalysis is an emerging technique for catalytic optimization. In order to make accurate predictions about the effects of an electric field on catalytic processes, formic acid decomposition is used as a model reaction. This is an ideal reaction, because it only has two simple reaction pathways: dehydrogenation (HCOOH → H2 + CO2) and dehydration (HCOOH → H2O + CO). Understanding the details of this mechanism is significant so that future researchers can make wise decisions on catalyst optimization during electric field reforming. Therefore, the catalytic decomposition of formic acid was investigated using 2 nm MoC particles supported on graphene as a catalyst. MoC nanoparticles were compared to commercial Mo2C. In order to verify a key mechanistic step of the reaction, various amounts of water (40, 50, 60, 70, 80, and 90 vol.%) were added to the feed over 0.50 mg of catalyst. Temperature programmed reaction using real-time gas analysis mass spectroscopy was used for these tests by heating the catalyst from 150 °C to 500 °C at a ramp rate of 10 °C/min. These experiments showed that the onset temperature of the reaction decreased in a linear fashion by approximately 100 °C as more water was added to the feed. This data indicates that a controversial key mechanistic step—the rotation of bidentate formate to monodentate formate on the surface—is very likely. This verifies that the reaction is highly dependent on molecular orientation of rate-limiting species, and that the use of an electric field should play a significant role in facilitating the reaction.