Decarbonisation Technology February 2026 Issue

process conditions and deactivation mechanisms. Short-life tests <5,000 h are not representative of end-of-life conditions, while accelerated ageing tests often do not enable realistic deactivation to occur. Catalyst performance was demonstrated, maintaining an operating regime where coke and carbon laydown was minimised and restricting per-pass conversion to reduce deactivation due to water partial pressures. Post-mortem analysis was conducted

Figure 3 Catalyst deactivation through sintering of cobalt particles shown by transmission electron microscopy (TEM)

to evaluate deactivation mechanisms. For example, X-ray diffraction, surface area, and elemental analysis were able to confirm minimal deactivation due to support degradation and poisoning. Microscopy was used to identify changes in the cobalt active sites through agglomeration and sintering from the fresh catalyst, which results in a lower cobalt surface area and reduced active sites concentration (see Figure 3 ). Advanced characterisation is vital to understand the nature of the catalyst under realistic process conditions (pressure, temperature, reactive gas environment, water partial pressures). For example, the role of water during catalyst activation is important to manage in order to achieve cobalt reduction and minimised sintering. Figure 4 shows the use of transmission electron microscopy with an in-situ cell to study catalyst particles during a reduction in hydrogen ( Lindley, et al., 2024 ). In operando X-ray tomography can show changes in catalyst pellets over time under syngas through deactivation mechanisms and byproduct formation ( Farooq, et al., 2024 ). This fundamental understanding is critical to deliver operational performance and ensure the process meets targets. Without this detailed understanding, there is a higher risk of unexpected performance failures and reduced economic delivery.

Continuous innovation Technical delivery of a competitive process at scale relies on continued innovation, fundamental understanding, and improvements. These include optimising and improving selectivity for target products, as well as stability and lifetime. These innovations can take the form of catalyst promoter effects to tune reactivity ( Paterson, et al., 2018 ), while support promoter effects play a key role in catalyst stability and lifetime. A deep technical understanding of the science and engineering is crucial to the continued development of

Figure 4 (left) In-situ TEM showing the change in cobalt particles and distribution as a function of reduction temperature, and (right ) in-situ X-ray tomography showing changes in the cobalt phase under syngas due to catalyst promoter (Mn)