| AVS 64th International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Wednesday Sessions |
| Session HC+NS+SS-WeM |
| Session: | Nanoscale Surface Structures in Heterogeneously-Catalyzed Reactions |
| Presenter: | Samuel Gage, Colorado School of Mines |
| Authors: | S. Gage, Colorado School of Mines K. Fong, Colorado School of Mines C. Ngo, Colorado School of Mines S. Shulda, Colorado School of Mines C. Tassone, SLAC National Accelerator Laboratory D. Nordlund, SLAC National Accelerator Laboratory R. Richards, Colorado School of Mines S. Pylypenko, Colorado School of Mines |
| Correspondent: | Click to Email |
Transition metal carbides and nitrides are an ever-growing topic in the scientific community. These materials can be synthesized with varying composition and morphology to exhibit properties similar to platinum-group metal catalysts, which are relevant to industrial heterogeneous catalysis and energy development. Studies, which report promising catalytic performances of nickel carbide and nitride catalysts, have continued to increase in recent years. Wet-chemical approaches involving a top-down thermal decomposition of nickel salt precursors in the presence of product-directing solvents are particularly interesting. The degree of nitrogen present in the nickel salt precursor, as well as the choice of molecular ligand-based solvents, can influence the material properties of the nickel carbide/nitride (Ni3C/Ni3N) products.
A series of nitrogen-rich and nitrogen-poor nickel salt precursors were thermally degraded in the presence of oleylamine. X-ray diffraction confirms the bulk hexagonal crystal structure belonging to Ni3C/Ni3N. However, a combination of bulk and surface X-ray characterization techniques, including the X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), small angle- and wide angle X-ray scattering (SAXS and WAXS) indicate that the material properties of the Ni3C/Ni3N nanostructures do vary depending on the precursor. Computationally guided experiments reveal that the unique bulk and surface properties of these nanostructures influence their catalytic activity, giving Ni3C/Ni3N nanostructures the potential to be earth-abundant substitutes for precious metal catalysts.