Catalytic properties and crystalline structures of manganese-promoted iron ultrafine particles for liquid-phase hydrogenation of carbon monoxide

Abstract Mn-promoted Fe ultrafine particle (UFP) catalysts for carbon monoxide hydrogenation exhibited a higher alkene selectivity and a lower methane selectivity than unpromoted Fe UFP. It was found, however, that the catalytic properties of the Mn-promoted Fe UFP catalysts, particularly the alkene selectivity, depended to a very large extent upon the level of carbon monoxide conversion. In the region of low carbon monoxide conversion, these catalysts more selectively produced olefinic hydrocarbons than in the region of high carbon monoxide conversion. Concurrently the bulk phase crystalline structures of these catalysts differed in both regions. Fe 2 C was formed in the region of low carbon monoxide conversion, and mixed oxides of iron and manganese were formed in the region of high carbon monoxide conversion.