NQR-NMR studies of higher alcohol synthesis Cu-Co catalysts. Quarterly technical progress report, June 15, 1994--September 15, 1994

摘要

The selectivity and conversion efficiency of the catalyst are reported to be governed by inter-metallic ratios of the three elements. High yields of methanol in copper-rich field, hydrocarbons in cobalt-rich field and mixed alcohols in the intermediate range were observed. The basic mechanism, the extent and effect of inter-metallic interactions, or the role and function of chromium still remain unclear. To examine the correspondence between the catalytic and magnetic behavior of the catalyst, the author has investigated the Zero-field Nuclear Magnetic Resonance spectra and Hysteresis character of a series of Cu/Co/Cr trimetallics with Cu/Co ratio varying from 0.2 to 8.0. The magnetic moment of the catalyst system is very low for Cu/Co < 1.5, dramatically increases when 1.5 < Cu/Co < 5.0 and drops for Cu/Co > 5.0. The NMR results indicate that chromium serves as a support and inhibits any strong intermetallic interaction between copper and cobalt.