On-board hydrogen production from urea via electrolysis to promote low-temperature catalytic reduction of NOx emissions

Nitrogen oxides emissions pose a significant environmental challenge, particularly in heavily industrialized, high-traffic regions. Global NOx levels continue to rise, despite various after treatment techniques being deployed to mitigate emission levels of combustion engine vehicles. Novel approaches to enhance NOx conversion efficiency at low exhaust temperatures (<200 C) include integrating hydrogen and ammonia injection before selective catalytic reduction modules. Urea electrolysis presents a promising avenue for simultaneous hydrogen and ammonia production. An anion exchange membrane electrolyser emerges as a viable and low-cost solution for on-board hydrogen production, offering compact size and compatibility with existing vehicle systems. Overcoming challenges such as catalyst and component selection, electrolyte viability, and system integration remains critical for realising the full potential of electrolysis-based NOx mitigation strategies in passenger vehicles.