Magnetic character investigation of higher alcohol synthesis Cu-Co-Cr catalysts

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, we have 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 5.0. The NMR results indicate that chromium serves as a support and inhibits any strong intermetallic interaction between copper and cobalt.