North America and Europe are implementing alternate fuels meet the goals of reducing carbon dioxide emissions and creating a sustainable environment. India too has promised to cut down emissions and become CO2 net neutral by 2070. One alternate fuel which has gained importance recently is hydrogen. With the announcement of National Hydrogen Mission by the Government of India in 2023, there has been an increased attention on the hydrogen fuel-based mobility. Technologies like H2-Fuel cell and a hydrogen fueled internal combustion engine (H2-ICE) are finding wider acceptance depending on the application and both offer an opportunity to meet targets of reduced carbon footprint in India and reduce reliance on fuel imports. A key advantage of H2-ICE is that its implementation requires little mod+ification to the conventional ICE. However, the internal combustion engine, even fueled with H2, still emits NOx and therefore must meet current and future regulations. NOx can be removed using Selective Catalytic Reduction (SCR) with ammonia (urea) as the reductant. Unlike current diesel engines, in which the water content is low (around 10%), H2-ICE may have 30% water in its exhaust which can affect NOx conversion efficiency, NH3 storage, N2O selectivity, or catalyst durability. In this study, the impact of water content on the deNOx performance, selectivity and durability of state-of-the-art BASF SCR technologies showed that water content had a minimal and manageable impact on SCR catalyst performance and that current zeolite and vanada based SCR catalyst will likely be adaptable to H2-ICE engine.
