An Efficient Catalyst for Light Olefins Production from CO Hydrogenation: Synergistic Effect of Zn and Ce Promoters on Performance of Co–Mn/SiO2 Catalyst

Abstract

The effectiveness of Fischer–Tropsch to olefins (FTO) synthesis could be improved by the design of new active catalysts with superior selectivity for light olefins and low methane production. The promoters including transition metal oxides and noble metals have been renowned to give high selectivity and activity in Fischer–Tropsch synthesis. An efficient approach for more selective synthesis of light olefins aiming to maximize the light olefins selectivity was achieved by using suitable reaction conditions. A novel Ce and Zn dual-decorated CobaltManganese catalyst supported on silica is studied. The catalyst was investigated in a fixed bed reactor with and without promoters to determine its potential for light olefins production. It was identified that a dual-decorated Ce–Zn catalyst increases the active sites of the catalyst due to the reducibility enhancement leading to higher selectivity to light olefins and lower selectivity to methane. The characterization of catalysts carried out by X-ray diffraction (XRD), temperature programmed reduction (TPR), scanning electron microscope (SEM), N2 adsorption–desorption measurements and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). All experiments were conducted with a CO/H2 feed ratio of 1 at 1 bar and 533 K. The resulting catalyst showed high CO conversion (>80%), high selectivity to light olefins and high olefin to paraffin ratio.