| The objective of this study was an understanding of the relationships between structural, chemical, and physical properties of Ni/SiO;Chemical and physical properties of Ni/SiO;These catalysts were used in ether formation reaction, x-ray photoelectron spectroscopy (Ni species identification), and 1,1-dimethylcyclopropane reaction (acid/metal function characterization) studies. These studies showed that the active site for ether formation in Ni/SiO;Ether formation activities of 0.7, 2.7, 4.7, and 8.5 weight% Ni/SiO;Increasing the drying temperature from 125 to 350;The optimal loading for ether formation activity was 2.7% weight%. This loading gave the highest ether formation selectivity: 94-97%. Ether formation activity has an inverse relationship to catalyst surface, reduced Ni; thus, the active site is not a large ensemble of zero valent Ni. Ether formation activity does not correlate with catalyst Ni silicate content because of synergistic effects from Ni(0) or physicochemical changes in Ni silicate with increasing metal loading. |
