407c Molecular Insight into Carbon Poisoning of Ni Surfaces: Dft-Guided Formulation of Carbon-Tolerant Steam Reforming Catalysts

Eranda Nikolla1, Johannes Schwank1, and Suljo Linic2. (1) Chemical Engineering, University of Michigan, 2300 Hayward, 3085 HH Dow, Ann Arbor, MI 48109, (2) Department of Chemical Engineering, University of Michigan, 2300 Hayward, Ann Arbor, MI 48109-2125

Density Functional Theory (DFT) calculations were utilized to study the surface chemistry of carbon atoms on Ni. These studies demonstrated that there is a strong thermodynamic driving force to form sp2-bonded carbon networks. It is believed that these extended carbon structures diminish the hydrocarbon reforming activity of Ni catalysts. We have further utilized DFT to search for Ni-containing alloy catalysts that might be more carbon-tolerant than monometallic Ni, i.e., that have a lower propensity to form the extended carbon networks. These studies have yielded a promising alloy formulation. We have tested the alloy under steady-state conditions in the steam reforming of various hydrocarbons. The reactor studies support the predictions of the first principles calculations.