Catalysis 2024 Issue

• Improved stability and durability • Precise tuning.

Catalytic upgrading of biomass-derived materials becomes essential. Researchers are actively developing catalysts tailored for the unique properties of bio-based feedstocks, contributing to the integration of renewable resources into traditional refining and petrochemical processes. Applications Titanium dioxide (TiO 2) is a versatile catalyst that finds applications in refining, such as a new low-density TiO 2 catalyst for improved sulphur recovery, such as what was presented by Johann Le Touze, Axens at SulGas Mumbai 2024. The presentation noted that about 50 million tons of SO 2 are prevented from being released into the atmosphere from Claus units loaded with Axens’ proprietary SulShine catalyst. According to information on Axens’ website, this recovery represented around 40% of the sulphur recovery from refinery and gas processing operations in 2016. This was at a time of peak fuel production prior to the global pandemic. Overall, low-density TiO 2 catalysts are of interest because they can offer specific advantages in terms of porosity, sur - face area, and catalytic activity, which is a good example of the types of catalysts playing a pivotal role in the refiner’s pursuit of creating value from a wider range of feedstocks. As noted, these catalysts often have a more porous struc- ture, providing a higher surface area for catalytic reactions. The increased surface area can enhance the catalyst’s effi - ciency in promoting reactions. Low-density catalysts can potentially reduce mass trans- fer limitations, allowing reactants to access active sites

Traditional catalysts often require a relatively high load- ing of expensive metal components. SACs, however, dis- tribute the active metal atoms more effectively, allowing for lower metal loadings while maintaining high catalytic activity. This reduction in metal usage contributes to cost savings and resource efficiency, including enhanced selec - tivity provided by well-dispersed active sites. According to a recently published research paper by Zhidong, et al in Nature , the authors noted that “although heterogeneous catalysts are widely used in industry [such as in refinery operations], their surface heterogeneity and structural complexity make it difficult to decipher the catalytic mech - anisms and improve catalyst atom efficiency”. Zhidong et al further explained that “SACs can enable the engineering of the coordination environment of the active center to establish structure-property relationships and elucidate the reaction mechanism”.1 Despite the current challenges and budget limitations, long-term opportunities seen with SACs allow for precise tuning of catalytic prop- erties by selecting different metal atoms and support mate- rials, enabling the design of catalysts optimised for specific reactions, leading to improved overall process efficiency. Bio-based feedstocks With growing scepticism surrounding the viability of electric vehicles, the importance of fossil feedstocks and co-processing of renewable feedstocks for fuels pro- duction, such as SAF, grows in diversity and importance.

Refinery processes typically involve high severity operations, so catalyst activity and stability are crucial

Catalysis 2024