High-throughput discovery of Hf promotion on the stabilisation of hcp Co and Fischer-Tropsch activity

A proxy-based high-throughput experimental approach was used to explore the stability and activity of Co-based Fischer-Tropsch Synthesis catalysts with different promoters on a variety of supports. The protocol is based on XRD estimation of the active phase polymorph, particle size and ratio of crystalline phases of Co to support. Sequential sample libraries enabled exploration of four Co loadings with five different promoters on six support materials. Catalysts stable to aging in syngas, i.e. displaying minimal change of particle size or active phase concentration, were evaluated under industrial conditions. This procedure identified SiC as a support that confers catalyst stability and that a combination of Ru and Hf promotes the stabilisation of hcp Co. Unsupported bulk samples of Co with appropriate amounts of Ru and Hf revealed that the formation of hcp Co is independent of the support. The hcp Co-containing catalyst afforded the highest catalytic activity and C5+ selectivity amongst the samples tested in this study, confirming the effectiveness of the proxy-based high-throughput method.