Towards improved conversion of wet waste to jet fuel with atomic layer deposition-coated hydrodeoxygenation catalysts

The conversion of wet waste-derived volatile fatty acids into jet fuel-range hydrocarbons is a promising route for increasing the production of sustainable aviation fuel; however, the cost and moderate alkane selectivity of Pt-based hydrodeoxygenation catalysts present challenges for commercialization. To address this, we used atomic layer deposition to apply TiO2 overcoats to Pt/Al2O3 catalysts and create new interface sites that exhibited 8 times higher site time yield of the desirable n-alkane product than uncoated catalyst. Through TPR/TPD, XPS, CO DRIFTS, and DFT calculations, we found that the increased selectivity of the ALD-coated catalyst was due to the creation of O vacancies at the Pt-TiO2 interface under reducing conditions, resulting in new Ti3+ acid sites near the active metal. Maximum conversion and alkane selectivity during HDO was achieved with an ALD-coated 0.5% wt Pt catalyst, indicating that TiO2 ALD can be used to maximize the utility of precious-metal catalysts.

Automated summary

The conversion of wet waste-derived volatile fatty acids into jet fuel-range hydrocarbons is a promising route for increasing sustainable aviation fuel production. However, the cost and moderate alkane selectivity of Pt-based hydrodeoxygenation catalysts pose challenges for commercialization. To address this, atomic layer deposition (ALD) was used to apply TiO2 overcoats to Pt/Al2O3 catalysts, resulting in significantly increased selectivity and yield of desirable n-alkane products.