An evaluation of the performance characteristics of SCR utilizing a Fe2O3–SiO2/Al2O3 synthesized catalyst for effective diesel engine exhaust emission reduction

Selective Catalytic Reduction (SCR) helps to reduce Nitrogen Oxide (NO) emissions from diesel engines using catalytic materials made of thermally stable non-precious metals. A dual support SCR catalyst using iron oxide (Fe₂O₃) and silica/alumina (SiO₂/Al₂O₃) has developed from low-cost materials. This catalyst has a monolith design for application to engines at full scale. The dual support provides a high level of interface between the iron oxide and silica/alumina that allows higher iron loadings, better iron distribution, and greater thermal stability of the Fe³⁺/Fe²⁺ redox couples across a wide temperature range (150-600 °C). Analytical techniques like (X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller Surface Area (BET) and Fourier Transform Infrared (FTIR) Spectroscopy confirmed the presence of a thermally stable and mesoporous catalyst with an even distribution of Lewis and Bronsted acid sites. Industrial applications of this catalyst have been performed on a diesel engine fuel as a diesel and diesel plastic oil blend (DPB) (B50) with a power output of 5.2 kW and significant conversion rates of 85% of NO at maximum load, and Hydrocarbons (HC), Carbon Monoxide (CO) and smoke opacity have been reduced by 65%, 55%, and 60%, respectively. Statistical analysis of results across all experimental conditions, including ANOVA, was conducted to establish the reproducibility of the findings. This catalyst exhibited consistent activity when tested with conventional diesel fuel as well as blended fuels composed of diesel and post-industrial waste. No precious metals or polymers have been used in the synthesis of the dual support SCR catalyst or subsequent formulations for commercial application. Overall, the results demonstrated that low-cost precursors could serve as effective catalysts for reducing NO emissions from diesel engines.